FOURTH AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF BIOMED REALTY, L.P.

EXHIBIT 10.1

FOURTH AMENDED AND RESTATED
AGREEMENT OF LIMITED PARTNERSHIP
OF
BIOMED REALTY, L.P.

          THIS FOURTH AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF BIOMED REALTY, L.P., A Maryland limited partnership (the “ Partnership ”), dated as of January 18, 2007, is entered into by and among BioMed Realty Trust, Inc., a Maryland corporation (the “ Company ”), as the General Partner, and the Persons whose names are set forth on Exhibit A attached hereto, as the Limited Partners, together with any other Persons who become Partners in the Partnership as provided herein.

          WHEREAS, the limited partnership was formed on April 30, 2004 and an original agreement of limited partnership was entered into between the Company, as general partner, and Alan D. Gold, as limited partner (the “ Original Partnership Agreement ”);

          WHEREAS, the Original Partnership Agreement was amended and restated by that certain Amended and Restated Agreement of Limited Partnership of BioMed Realty, L.P., dated as of August 11, 2004 (the “ First Amended and Restated Partnership Agreement ”), by and between the Company, as general partner and limited partner, and Alan D. Gold, as limited partner (together, the “ Current Partners ”), in connection with the initial public offering of the Company’s common stock;

          WHEREAS, the First Amended and Restated Partnership Agreement, by and among the current Partners was amended and restated by the Second Amended and Restated Agreement of Limited Partnership of the Partnership (the “ Second Amended and Restated Partnership Agreement ”), dated August 13, 2004;

          WHEREAS, the Second Amended and Restated Partnership Agreement, by and among the current Partners was amended and restated by the Third Amended and Restated Agreement of Limited Partnership of the Partnership (the “ Third Amended and Restated Partnership Agreement ”), dated December 28, 2006; and

          WHEREAS, the Current Partners and the Partnership believe it is desirable and in the best interest of the Partnership to amend and restate the Third Amended and Restated Partnership Agreement, in its entirety, as set forth herein.

          NOW, THEREFORE, BE IT RESOLVED, that the Current Partners and the Partnership hereby amend and restate the Third Amended and Restated Partnership Agreement as follows:

ARTICLE 1.
DEFINED TERMS

Section 1.1 Definitions .

          The following definitions shall be for all purposes, unless otherwise clearly indicated to the contrary, applied to the terms used in this Agreement.

          “ Act ” means the Maryland Revised Uniform Limited Partnership Act, as it may be amended from time to time, and any successor to such statute.

          “ Additional Funds ” shall have the meaning set forth in Section 4.3.A .

          “ Additional Limited Partner ” means a Person admitted to the Partnership as a Limited Partner pursuant to Section 12.2 and who is shown as such on the books and records of the Partnership.

          “ Adjusted Capital Account Deficit ” means, with respect to any Partner, the deficit balance, if any, in such Partner’s Capital Account as of the end of the relevant fiscal year, after giving effect to the following adjustments:

	(i)		such deficit shall be decreased by any amounts which such Partner is obligated to restore pursuant to this Agreement or is deemed to be obligated to restore pursuant to Regulations Section 1.704-1(b)(2)(ii)(c) or the penultimate sentence of each of Regulations Sections 1.704-2(i)(5) and 1.704-2(g)(1); and
	(ii)		such deficit shall be increased by the items described in Regulations Section 1.704-1(b)(2)(ii)(d)(4), (5) and (6).

          The foregoing definition of Adjusted Capital Account Deficit is intended to comply with the provisions of Regulations Section 1.704-1(b)(2)(ii)(d) and shall be interpreted consistently therewith. A positive balance in a Partner’s Capital Account, after giving effect to the adjustments described above in clauses (i) and (ii), is referred to in this Agreement as an “ Adjusted Capital Account Balance .”

          “ Adjustment Date ” means, with respect to any Capital Contribution, the close of business on the Business Day last preceding the date of the Capital Contribution, provided , that if such Capital Contribution is being made by the General Partner in respect of the proceeds from the issuance of REIT Shares (or the issuance of the General Partner’s securities exercisable for, convertible into or exchangeable for REIT Shares), then the Adjustment Date shall be as of the close of business on the Business Day last preceding the date of the issuance of such securities.

          “ Affiliate ” means, with respect to any Person, any Person directly or indirectly controlling, controlled by or under common control with such Person. Control of any Person means the power to direct the management and policies of such Person, directly or indirectly, whether through the ownership of voting securities, by contract or otherwise, and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

          “ Agreed Value ” means (i) in the case of any Contributed Property set forth in Exhibit A and as of the time of its contribution to the Partnership, the Agreed Value of such property as set forth in Exhibit A ; (ii) in the case of any Contributed Property not set forth in Exhibit A and as of the time of its contribution to the Partnership, the fair market value of such property or other consideration as determined by the General Partner, reduced by any liabilities either assumed by the Partnership upon such contribution or to which such property is subject when contributed; and (iii) in the case of any property distributed to a Partner by the Partnership, the fair market value of such property as determined by the General Partner at the time such property is distributed, reduced by any liabilities either assumed by such Partner upon such distribution or to which such property is subject at the time of the distribution as determined under Section 752 of the Code and the Regulations thereunder.

          “ Agreement ” means this Fourth Amended and Restated Agreement of Limited Partnership, as it may be amended, modified, supplemented or restated from time to time.

          “ Appraisal ” means with respect to any assets, the opinion of an independent third party experienced in the valuation of similar assets, selected by the General Partner in good faith; such opinion may be in the form of an opinion by such independent third party that the value for such property or asset as set by the General Partner is fair, from a financial point of view, to the Partnership.

          “ Assignee ” means a Person to whom one or more Partnership Units have been transferred in a manner permitted under this Agreement, but who has not become a Substituted Limited Partner, and who has the rights set forth in Section 11.5 .

          “ Available Cash ” means, with respect to any period for which such calculation is being made,

          (i) the sum of:

     a. the Partnership’s Net Income or Net Loss (as the case may be) for such period,

     b. Depreciation and all other noncash charges deducted in determining Net Income or Net Loss for such period,

     c. the amount of any reduction in reserves of the Partnership referred to in clause (ii)(f) below (including, without limitation, reductions resulting because the General Partner determines such amounts are no longer necessary),

     d. the excess of the net proceeds from the sale, exchange, disposition, or refinancing of Partnership property for such period over the gain (or loss, as the case may be) recognized from any such sale, exchange, disposition, or refinancing during such period (excluding any sale or other disposition of all or substantially all of the assets of the Partnership or a related series of transactions that, taken together, result in the sale or other disposition of all or substantially all of the assets of the Partnership), and

     e. all other cash received by the Partnership for such period that was not included in determining Net Income or Net Loss for such period;

          (ii) less the sum of:

     a. all principal debt payments made during such period by the Partnership,

     b. capital expenditures made by the Partnership during such period,

     c. investments in any entity (including loans made thereto) to the extent that such investments are not otherwise described in clauses (ii)(a) or (b),

     d. all other expenditures and payments not deducted in determining Net Income or Net Loss for such period,

     e. any amount included in determining Net Income or Net Loss for such period that was not received by the Partnership during such period,

     f. the amount of any increase in reserves established during such period which the General Partner determines are necessary or appropriate in its sole and absolute discretion,

     g. the amount of any working capital accounts and other cash or similar balances which the General Partner determines to be necessary or appropriate in its sole and absolute discretion, and

     h. any amount paid in redemption of any Limited Partner Interest or Partnership Units, including any Cash Amount paid.

          Notwithstanding the foregoing, Available Cash shall not include any cash received or reductions in reserves, or take into account any disbursements made or reserves established, after commencement of the dissolution and liquidation of the Partnership.

          “ Book-up Event ” means an event described in any of clauses (b)(i) through (v) of the definition of Gross Asset Value.

          “ Book-up Value ” has the meaning set forth in Section 6.3.B.

          “ Business Day ” means any day except a Saturday, Sunday or other day on which commercial banks in New York, New York are authorized or required by law to be closed.

          “ Capital Account ” means, with respect to any Partner, the Capital Account maintained for such Partner in accordance with the following provisions:

          (a) To each Partner’s Capital Account there shall be added such Partner’s Capital Contributions, such Partner’s share of Net Income and any items in the nature of income or gain which are specially allocated pursuant to Section 6.3 , and the amount of any Partnership

liabilities assumed by such Partner or which are secured by any property distributed to such Partner.

          (b) From each Partner’s Capital Account there shall be subtracted the amount of cash and the Gross Asset Value of any property distributed to such Partner pursuant to any provision of this Agreement, such Partner’s distributive share of Net Losses and any items in the nature of expenses or losses which are specially allocated pursuant to Section 6.3 , and the amount of any liabilities of such Partner assumed by the Partnership or which are secured by any property contributed by such Partner to the Partnership (except to the extent already reflected in the amount of such Partner’s Capital Contribution).

          (c) In the event any interest in the Partnership is transferred in accordance with the terms of this Agreement (which does not result in a termination of the Partnership for federal income tax purposes), the transferee shall succeed to the Capital Account of the transferor to the extent it relates to the transferred interest.

          (d) In determining the amount of any liability for purposes of subsections (a) and (b) hereof, there shall be taken into account Code Section 752(c) and any other applicable provisions of the Code and Regulations.

          (e) The foregoing provisions and the other provisions of this Agreement relating to the maintenance of Capital Accounts are intended to comply with Regulations Sections 1.704-1(b) and 1.704-2, and shall be interpreted and applied in a manner consistent with such Regulations. In the event the General Partner shall determine that it is prudent to modify the manner in which the Capital Accounts, or any debits or credits thereto (including, without limitation, debits or credits relating to liabilities which are secured by contributed or distributed property or which are assumed by the Partnership, the General Partner, or the Limited Partners) are computed in order to comply with such Regulations, the General Partner may make such modification, provided that it is not likely to have a material effect on the amounts distributable to any Person pursuant to Article 13 of this Agreement upon the dissolution of the Partnership. The General Partner also shall (i) make any adjustments that are necessary or appropriate to maintain equality between the Capital Accounts of the Partners and the amount of Partnership capital reflected on the Partnership’s balance sheet, as computed for book purposes, in accordance with Regulations Section 1.704-1(b)(2)(iv)(q), and (ii) make any appropriate modifications in the event unanticipated events might otherwise cause this Agreement not to comply with Regulations Section 1.704-1(b) or Section 1.704-2.

          “ Capital Contribution ” means, with respect to any Partner, the amount of money and the initial Gross Asset Value of any property (other than money) contributed to the Partnership by such Partner (net of any liabilities assumed by the Partnership relating to such property and any liability to which such property is subject).

          “ Cash Amount ” means, with respect to any Partnership Units subject to a Redemption, an amount of cash equal to the Deemed Partnership Interest Value attributable to such Partnership Units.

          “ Certificate ” means the Certificate of Limited Partnership relating to the Partnership filed in the office of the State Department of Assessments and Taxation of Maryland on April 30, 2004, as amended from time to time in accordance with the terms hereof and the Act.

          “ Change of Control ” shall be deemed to have occurred at such time as (i) the date a “person” or “group” (within the meaning of Sections 13(d) and 14(d) of the Exchange Act becomes the ultimate “beneficial owner” (as defined in Rules 13d-3 and 13d-5 under the Exchange Act, except that a person or group shall be deemed to have beneficial ownership of all shares of voting stock that such person or group has the right to acquire regardless of when such right is first exercisable), directly or indirectly, of voting stock representing more than 50% of the total voting power of the total voting stock of the General Partner; (ii) the date the General Partner sells, transfers or otherwise disposes of all or substantially all of its assets; or (iii) the date of the consummation of a merger or share exchange of the General Partner with another entity where the General Partner’s stockholders immediately prior to the merger or share exchange would not beneficially own, immediately after the merger or share exchange, shares representing 50% or more of all votes (without consideration of the rights of any class of stock to elect directors by a separate group vote) to which all stockholders of the corporation issuing cash or securities in the merger or share exchange would be entitled in the election of directors, or where members of the board of directors of the General Partner immediately prior to the merger or share exchange would not immediately after the merger or share exchange constitute a majority of the board of directors of the corporation issuing cash or securities in the merger or share exchange.

          “ Charter ” means the Articles of Incorporation of the General Partner filed with the State Department of Assessments and Taxation of Maryland on April 30, 2004, as amended or restated from time to time.

          “ Code ” means the Internal Revenue Code of 1986, as amended from time to time or any successor statute thereto. Any reference herein to a specific section or sections of the Code shall be deemed to include a reference to any corresponding provision of future law.

          “ Consent ” means the consent to, approval of, or vote on a proposed action by a Partner given in accordance with Article 14 .

          “ Consent of the Limited Partners ” means the Consent of a Majority in Interest of the Limited Partners, which Consent shall be obtained prior to the taking of any action for which it is required by this Agreement and may be given or withheld by a Majority in Interest of the Limited Partners, unless otherwise expressly provided herein, in their sole and absolute discretion.

          “ Consent of the Partners ” means the Consent of Partners holding Percentage Interests that in the aggregate are equal to or greater than fifty percent (50%) of the aggregate Percentage Interests of all Partners, which Consent shall be obtained prior to the taking of any action for which it is required by this Agreement and may be given or withheld by such Partners, in their sole and absolute discretion.

          “ Constructively Own ” means ownership under the constructive ownership rules described in Exhibit C .

          “ Contributed Property ” means each property or other asset, in such form as may be permitted by the Act, but excluding cash, contributed or deemed contributed to the Partnership (or, to the extent provided in applicable Regulations, deemed contributed to the Partnership on termination and reconstitution thereof pursuant to Section 708 of the Code).

          “ Debt ” means, as to any Person, as of any date of determination, (i) all indebtedness of such Person for borrowed money or for the deferred purchase price of property or services; (ii) all amounts owed by such Person to banks or other Persons in respect of reimbursement obligations under letters of credit, surety bonds, guarantees and other similar instruments guaranteeing payment or other performance of obligations by such Person; (iii) all indebtedness for borrowed money or for the deferred purchase price of property or services secured by any lien on any property owned by such Person, to the extent attributable to such Person’s interest in such property, even though such Person has not assumed or become liable for the payment thereof; and (iv) lease obligations of such Person which, in accordance with generally accepted accounting principles, should be capitalized.

          “ Deemed Partnership Interest Value ” means, as of any date with respect to any class of Partnership Interests, the Deemed Value of the Partnership Interests of such class multiplied by the applicable Partner’s Percentage Interest of such class.

          “ Deemed Value of the Partnership Interests ” means, as of any date with respect to any class or series of Partnership Interests, (i) the total number of Partnership Units of the General Partner in such class or series of Partnership Interests (as provided for in Sections 4.1 and 4.3.B ) issued and outstanding as of the close of business on such date multiplied by the Fair Market Value determined as of such date of a share of capital stock of the General Partner which corresponds to such class or series of Partnership Interests, as adjusted (x) pursuant to Section 7.5 (in the event the General Partner acquires material assets, other than on behalf of the Partnership) and (y) for stock dividends and distributions, stock splits and subdivisions, reverse stock splits and combinations, distribution of warrants or options and distributions of evidences of indebtedness or assets not received by the General Partner pursuant to a pro rata distribution by the Partnership; (ii) divided by the Percentage Interest of the General Partner in such class or series of Partnership Interests on such date; provided , that if no outstanding shares of capital stock of the General Partner correspond to a class of series of Partnership Interests, the Deemed Value of the Partnership Interests with respect to such class or series shall be equal to an amount reasonably determined by the General Partner.

          “ Depreciation ” means, for each fiscal year or other period, an amount equal to the depreciation, amortization or other cost recovery deduction allowable with respect to an asset for such year or other period, except that if the Gross Asset Value of an asset differs from its adjusted basis for federal income tax purposes at the beginning of such year or other period, Depreciation shall be an amount which bears the same ratio to such beginning Gross Asset Value as the federal income tax depreciation, amortization or other cost recovery deduction for such year or other period bears to such beginning adjusted tax basis; provided , however , that if the federal income tax depreciation, amortization or other cost recovery deduction for such year is

zero, Depreciation shall be determined with reference to such beginning Gross Asset Value using any reasonable method selected by the General Partner.

          “ Economic Capital Account Balance ” shall mean the Capital Account balance of an LTIP Unitholder as computed for book purposes but, for purposes of this definition, not reduced by the amount of any Tax Distributions to such LTIP Unitholder, plus the amount of such Partner’s share of any Partner Minimum Gain or Partnership Minimum Gain, in either case to the extent attributable to such Partner’s ownership of LTIP Units.

          “ Effective Date ” means the date of closing of the initial public offering of REIT Shares upon which date the contributions set forth on Exhibit A shall become effective.

          “ ERISA ” means the Employee Retirement Income Security Act of 1974, as amended.

          “ Exchange Act ” means the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Securities and Exchange Commission promulgated thereunder and any successor statute thereto.

          “ Fair Market Value ” means, with respect to any share of capital stock of the General Partner, the average of the daily market price for the ten (10) consecutive trading days immediately preceding the date with respect to which “Fair Market Value” must be determined hereunder or, if such date is not a Business Day, the immediately preceding Business Day. The market price for each such trading day shall be: (i) if such shares are listed or admitted to trading on any securities exchange or the Nasdaq National Market, the closing price, regular way, on such day, or if no such sale takes place on such day, the average of the closing bid and asked prices on such day, (ii) if such shares are not listed or admitted to trading on any securities exchange or the Nasdaq National Market, the last reported sale price on such day or, if no sale takes place on such day, the average of the closing bid and asked prices on such day, as reported by a reliable quotation source designated by the General Partner, or (iii) if such shares are not listed or admitted to trading on any securities exchange or the Nasdaq National Market and no such last reported sale price or closing bid and asked prices are available, the average of the reported high bid and low asked prices on such day, as reported by a reliable quotation source designated by the General Partner, or if there shall be no bid and asked prices on such day, the average of the high bid and low asked prices, as so reported, on the most recent day (not more than ten (10) days prior to the date in question) for which prices have been so reported; provided that , if there are no bid and asked prices reported during the ten (10) days prior to the date in question, the Fair Market Value of such shares shall be determined by the General Partner acting in good faith on the basis of such quotations and other information as it considers, in its reasonable judgment, appropriate. In the event the REIT Shares Amount for such shares includes rights that a holder of such shares would be entitled to receive, then the Fair Market Value of such rights shall be determined by the General Partner acting in good faith on the basis of such quotations and other information as it considers, in its reasonable judgment, appropriate; and provided , further that , in connection with determining the Deemed Value of the Partnership Interests for purposes of determining the number of additional Partnership Units issuable upon a Capital Contribution funded by an underwritten public offering of shares of capital stock of the General Partner, the Fair Market Value of such shares shall be the public offering price per share

of such class of capital stock sold. Notwithstanding the foregoing, the General Partner in its reasonable discretion may use a different “Fair Market Value” for purposes of making the determinations under subparagraph (b) of the definition of “Gross Asset Value” and Section 4.3.D in connection with the contribution of Property or cash to the Partnership by a third party, provided such value shall be based upon the value per REIT Share (or per Partnership Unit) agreed upon by the General Partner and such third party for purposes of such contribution.

          “ Forfeitable LTIP Units ” has the meaning set forth in Section 4.6 hereof.

          “ General Partner ” means the Company or its successor as general partner of the Partnership.

          “ General Partner Interest ” means a Partnership Interest held by the General Partner. A General Partner Interest may be expressed as a number of Partnership Units.

          “ Gross Asset Value ” means, with respect to any asset, the asset’s adjusted basis for federal income tax purposes, except as follows:

          (a) The initial Gross Asset Value of any asset contributed by a Partner to the Partnership shall be the gross fair market value of such asset, as determined by the contributing Partner and the General Partner (as set forth on Exhibit A attached hereto, as such Exhibit may be amended from time to time); provided , that if the contributing Partner is the General Partner, then, except with respect to the General Partner’s initial Capital Contribution which shall be determined as set forth on Exhibit A , the determination of the fair market value of the contributed asset shall be determined (i) by the price paid by the General Partner if the asset is acquired by the General Partner contemporaneously with its contribution to the Partnership, (ii) by Appraisal, if otherwise acquired by the General Partner, (iii) by the amount of cash if the asset is cash, and (iv) as reasonably determined by the General Partner if the asset is REIT Shares or other shares of capital stock of the Company.

          (b) The Gross Asset Values of all Partnership assets shall be adjusted to equal their respective gross fair market values, as determined by the General Partner using such reasonable method of valuation as it may adopt, provided , however , that for such purpose, the net value of all of the Partnership assets, in the aggregate, shall be equal to the Deemed Value of the Partnership Interests of all classes of Partnership Interests then outstanding, regardless of the method of valuation adopted by the General Partner, immediately prior to the times listed below:

	(i)		the acquisition of an additional interest in the Partnership by a new or existing Partner in exchange for more than a de minimis Capital Contribution, if the General Partner reasonably determines that such adjustment is necessary or appropriate to reflect the relative economic interests of the Partners in the Partnership;
	(ii)		the distribution by the Partnership to a Partner of more than a de minimis amount of Partnership property as consideration for an interest in the Partnership if the General Partner reasonably determines that such adjustment is necessary or appropriate to reflect the relative economic interests of the Partners in the Partnership;

	(iii)		the liquidation of the Partnership within the meaning of Regulations Section 1.704-1(b)(2)(ii)(g);
	(iv)		at such other times as the General Partner shall reasonably determine necessary or advisable in order to comply with Regulations Sections 1.704-1(b) and 1.704-2; and
	(v)		in connection with the grant of an interest in the Partnership (other than a de minimis interest) as consideration for the provision of services to or for the benefit of the Partnership by an existing Partner acting in a partner capacity or by a new Partner acting in a partner capacity or in anticipation of becoming a Partner (including the grant of any LTIP Units).

          (c) The Gross Asset Value of any Partnership asset distributed to a Partner shall be the gross fair market value of such asset on the date of distribution as determined by the distributee and the General Partner, or if the distributee and the General Partner cannot agree on such a determination, by Appraisal.

          (d) The Gross Asset Values of Partnership assets shall be increased (or decreased) to reflect any adjustments to the adjusted basis of such assets pursuant to Code Section 734(b) or Code Section 743(b), but only to the extent that such adjustments are taken into account in determining Capital Accounts pursuant to Regulations Section 1.704-1(b)(2)(iv)(m); provided , however , that Gross Asset Values shall not be adjusted pursuant to this subparagraph (d) to the extent that the General Partner reasonably determines that an adjustment pursuant to subparagraph (b) is necessary or appropriate in connection with a transaction that would otherwise result in an adjustment pursuant to this subparagraph (d).

          (e) If the Gross Asset Value of a Partnership asset has been determined or adjusted pursuant to subparagraph (a), (b) or (d), such Gross Asset Value shall thereafter be adjusted by the Depreciation taken into account with respect to such asset for purposes of computing Net Income and Net Losses.

          (f) Upon a Book-up Event, the Gross Asset Value of each Partnership asset shall be determined as provided in Section 6.3.B(1).

          “ Holder ” means either the Partner or Assignee owning a Partnership Unit, that is treated as a partner of the Partnership for federal income tax purposes.

          “ Immediate Family ” means, with respect to any natural Person, such natural Person’s estate or heirs or current spouse or former spouse, parents, parents-in-law, children (whether natural, adopted or by marriage), siblings and grandchildren and any trust or estate, all of the beneficiaries of which consist of such Person or such Person’s spouse or former spouse, parents, parents-in-law, children, siblings or grandchildren.

          “ Incapacity ” or “ Incapacitated ” means, (i) as to any individual Partner, death, total physical disability or entry by a court of competent jurisdiction adjudicating him or her incompetent to manage his or her Person or his or her estate; (ii) as to any corporation which is a Partner, the filing of a certificate of dissolution, or its equivalent, for the corporation or the

revocation of its charter; (iii) as to any partnership which is a Partner, the dissolution and commencement of winding up of the partnership; (iv) as to any estate which is a Partner, the distribution by the fiduciary of the estate’s entire interest in the Partnership; (v) as to any trustee of a trust which is a Partner, the termination of the trust (but not the substitution of a new trustee); or (vi) as to any Partner, the bankruptcy of such Partner. For purposes of this definition, bankruptcy of a Partner shall be deemed to have occurred when (a) the Partner commences a voluntary proceeding seeking liquidation, reorganization or other relief under any bankruptcy, insolvency or other similar law now or hereafter in effect, (b) the Partner is adjudged as bankrupt or insolvent, or a final and nonappealable order for relief under any bankruptcy, insolvency or similar law now or hereafter in effect has been entered against the Partner, (c) the Partner executes and delivers a general assignment for the benefit of the Partner’s creditors, (d) the Partner files an answer or other pleading admitting or failing to contest the material allegations of a petition filed against the Partner in any proceeding of the nature described in clause (b) above, (e) the Partner seeks, consents to or acquiesces in the appointment of a trustee, receiver or liquidator for the Partner or for all or any substantial part of the Partner’s properties, (f) any proceeding seeking liquidation, reorganization or other relief under any bankruptcy, insolvency or other similar law now or hereafter in effect has not been dismissed within 120 days after the commencement thereof, (g) the appointment without the Partner’s consent or acquiescence of a trustee, receiver or liquidator has not been vacated or stayed within 90 days of such appointment, or (h) an appointment referred to in clause (g) is not vacated within 90 days after the expiration of any such stay.

          “ Indemnitee ” means (i) any Person subject to a claim or demand or made or threatened to be made a party to, or involved or threatened to be involved in, an action, suit or proceeding by reason of his or her status as (A) the General Partner or (B) a director or officer of the Partnership or the General Partner, and (ii) such other Persons (including Affiliates of the General Partner or the Partnership) as the General Partner may designate from time to time (whether before or after the event giving rise to potential liability), in its sole and absolute discretion.

          “ IRS ” means the United States Internal Revenue Service.

          “ Junior Units ” means Partnership Units representing any class or series of Partnership Interest ranking, as to distributions or voluntary or involuntary liquidation, dissolution or winding-up of the Partnership, junior to the Series A Preferred Units.

          “ Limited Partner ” means any Person named as a Limited Partner in Exhibit A attached hereto, as such Exhibit may be amended from time to time, or any Substituted Limited Partner or Additional Limited Partner, in such Person’s capacity as a Limited Partner in the Partnership.

          “ Limited Partner Interest ” means a Partnership Interest of a Limited Partner representing a fractional part of the Partnership Interests of all Limited Partners and includes any and all benefits to which the Holder of such a Partnership Interest may be entitled as provided in this Agreement, together with all obligations of such Person to comply with the terms and provisions of this Agreement. A Limited Partner Interest may be expressed as a number of Partnership Units.

          “ Liquidating Event ” shall have the meaning set forth in Section 13.1 .

          “ Liquidator ” shall have the meaning set forth in Section 13.2.A .

          “ LTIP Equalization Date ” has the meaning set forth in Section 6.3.B(1).

          “ LTIP Forfeiture Agreement ” means each Long Term Incentive Plan (LTIP) Unit Agreement entered into by a LTIP Unitholder upon acceptance of a grant of LTIP Units (as such agreement may be amended, modified or supplemented from time to time).

          “ LTIP Unit ” means a Partnership Unit which is designated as an “LTIP Unit”, which represents a profits interest in future appreciation and certain distributions of Available Cash, and which has the rights, preferences and other privileges designated in Section 4.6 hereof and elsewhere in this Agreement in respect of Holders of LTIP Units. The allocation of LTIP Units among the Partners shall be set forth on Exhibit A, as may be amended from time to time by the General Partner as it approves the grant of additional LTIP Units. An LTIP Unit shall be deemed to be a Partnership Unit (A) that may be the subject of a Redemption only when both (i) the LTIP Unit has become a Non-Forfeitable LTIP Unit and (ii) the LTIP Equalization Date has occurred as provided in Section 4.6, and (B) for purposes of distributions of Available Cash and allocations to the extent provided in Sections 4.6.B, 5.1 and 6.3.B.

          “ LTIP Unitholder ” means a Partner that holds LTIP Units.

          “ Majority in Interest of the Limited Partners ” means Limited Partners holding in the aggregate Percentage Interests that are greater than fifty percent (50%) of the aggregate Percentage Interests of all Limited Partners.

          “ Net Income ” or “ Net Loss ” means for each fiscal year of the Partnership, an amount equal to the Partnership’s taxable income or loss for such fiscal year, determined in accordance with Code Section 703(a) (for this purpose, all items of income, gain loss, or deduction required to be stated separately pursuant to Code Section 703(a)(1) shall be included in taxable income or loss), with the following adjustments:

          (a) Any income of the Partnership that is exempt from federal income tax and not otherwise taken into account in computing Net Income or Net Loss pursuant to this definition of Net Income or Net Loss shall be added to such taxable income or loss;

          (b) Any expenditures of the Partnership described in Code Section 705(a)(2)(B) or treated as Code Section 705(a)(2)(B) expenditures pursuant to Regulations Section 1.704-1(b)(2)(iv)(i), and not otherwise taken into account in computing Net Income or Net Loss pursuant to this definition of Net Income or Net Loss shall be subtracted from such taxable income or loss;

          (c) In the event the Gross Asset Value of any Partnership asset is adjusted pursuant to subparagraph (b) or subparagraph (c) of the definition of Gross Asset Value, the amount of such adjustment shall be taken into account as gain or loss from the disposition of such asset for purposes of computing Net Income or Net Loss;

          (d) Gain or loss resulting from any disposition of property with respect to which gain or loss is recognized for federal income tax purposes shall be computed by reference to the Gross Asset Value of the property disposed of, notwithstanding that the adjusted tax basis of such property differs from its Gross Asset Value;

          (e) In lieu of the depreciation, amortization, and other cost recovery deductions taken into account in computing such taxable income or loss, there shall be taken into account Depreciation for such fiscal year;

          (f) To the extent an adjustment to the adjusted tax basis of any Partnership asset pursuant to Code Section 734(b) or Code Section 743(b) is required pursuant to Regulations Section 1.704-1(b)(2)(iv)(m)(4) to be taken into account in determining Capital Accounts as a result of a distribution other than in liquidation of a Partner’s interest in the Partnership, the amount of such adjustment shall be treated as an item of gain (if the adjustment increases the basis of the asset) or loss (if the adjustment decreases the basis of the asset) from the disposition of the asset and shall be taken into account for purposes of computing Net Income or Net Loss; and

          (g) Notwithstanding any other provision of this definition of Net Income or Net Loss, any items which are specially allocated pursuant to Section 6.3 shall not be taken into account in computing Net Income or Net Loss. The amounts of the items of Partnership income, gain, loss, or deduction available to be specially allocated pursuant to Section 6.3 shall be determined by applying rules analogous to those set forth in this definition of Net Income or Net Loss.

          “ New Securities ” means (i) any rights, options, warrants or convertible or exchangeable securities having the right to subscribe for or purchase REIT Shares or other shares of capital stock of the General Partner, excluding in each case, grants under any Stock Plan, or (ii) any Debt issued by the General Partner that provides any of the rights described in clause (i).

          “ Non-Forfeitable LTIP Units ” has the meaning set forth in Section 4.6.D(1) hereof.

          “ Nonrecourse Deductions ” shall have the meaning set forth in Regulations Section 1.704-2(b)(1), and the amount of Nonrecourse Deductions for a Partnership Year shall be determined in accordance with the rules of Regulations Section 1.704-2(c).

          “ Nonrecourse Liability ” shall have the meaning set forth in Regulations Section 1.752-1(a)(2).

          “ Notice of Redemption ” means the Notice of Redemption substantially in the form of Exhibit B to this Agreement.

          “ Parity Preferred Unit ” means any class or series of Partnership Interests of the Partnership now or hereafter authorized, issued or outstanding expressly designated by the Partnership to rank on a parity with the Series A Preferred Units with respect to distributions or rights upon voluntary or involuntary liquidation, winding-up or dissolution of the Partnership, or both, as the context may require.

          “ Partner ” means a General Partner or a Limited Partner, and “ Partners ” means the General Partner and the Limited Partners.

          “ Partner Minimum Gain ” means an amount, with respect to each Partner Nonrecourse Debt, equal to the Partnership Minimum Gain that would result if such Partner Nonrecourse Debt were treated as a Nonrecourse Liability, determined in accordance with Regulations Section 1.704-2(i)(3).

          “ Partner Nonrecourse Debt ” shall have the meaning set forth in Regulations Section 1.704-2(b)(4).

          “ Partner Nonrecourse Deductions ” shall have the meaning set forth in Regulations Section 1.704-2(i)(2), and the amount of Partner Nonrecourse Deductions with respect to a Partner Nonrecourse Debt for a Partnership Year shall be determined in accordance with the rules of Regulations Section 1.704-2(i)(2).

          “ Partnership ” means the limited partnership formed under the Act and pursuant to this Agreement, and any successor thereto.

          “ Partnership Unit Economic Balance ” has the meaning set forth in Section 6.3.B(3).

          “ Partnership Interest ” means, an ownership interest in the Partnership of either a Limited Partner or the General Partner and includes any and all benefits to which the holder of such a Partnership Interest may be entitled as provided in this Agreement, together with all obligations of such Person to comply with the terms and provisions of this Agreement. There may be one or more classes or series of Partnership Interests as provided in Section 4.3 . A Partnership Interest may be expressed as a number of Partnership Units. Unless otherwise expressly provided for by the General Partner at the time of the original issuance of any Partnership Interests, all Partnership Interests (whether of a Limited Partner or a General Partner) shall be of the same class or series.

          “ Partnership Minimum Gain ” shall have the meaning set forth in Regulations Section 1.704-2(b)(2), and the amount of Partnership Minimum Gain, as well as any net increase or decrease in Partnership Minimum Gain, for a Partnership Year shall be determined in accordance with the rules of Regulations Section 1.704-2(d).

          “ Partnership Record Date ” means the record date established by the General Partner for the distribution of Available Cash pursuant to Section 5.1 which record date shall be the same as the record date established by the General Partner for a distribution to its stockholders of some or all of its portion of such distribution.

          “ Partnership Unit ” or “ Unit ” means, with respect to any class of Partnership Interest, a fractional, undivided share of such class of Partnership Interest issued pursuant to Sections 4.1 and 4.3 . The ownership of Partnership Units may be evidenced by a certificate for units substantially in the form of Exhibit D hereto or as the General Partner may determine with respect to any class of Partnership Units issued from time to time under Section 4.1 and 4.3 . Partnership Units include LTIP Units to the extent set forth in the definition of “LTIP Units.”

          “ Partnership Year ” means the fiscal year of the Partnership, which shall be the calendar year.

          “ Percentage Interest ” means, as to a Partner holding a class or series of Partnership Interests, its interest in such class or series as determined by dividing the Partnership Units of such class or series owned by such Partner by the total number of Partnership Units of such class then outstanding as specified in Exhibit A attached hereto, as such Exhibit may be amended from time to time. If the Partnership issues more than one class or series of Partnership Interests, the interest in the Partnership among the classes or series of Partnership Interests shall be determined as set forth in the amendment to the Partnership Agreement setting forth the rights and privileges of such additional classes or series of Partnership Interest, if any, as contemplated by Section 4.3.D .

          “ Person ” means an individual, corporation, partnership, limited liability company, trust, unincorporated organization, association or other entity.

          “ Plan Asset Regulation ” means the regulations promulgated by the United States Department of Labor in Title 29, Code of Federal Regulations, Part 2510, Section 101.3, and any successor regulations thereto.

          “ Pledge ” shall have the meaning set forth in Section 11.3.A .

          “ Post-Grant Gains ” shall have the meaning set forth in Section 6.3.B hereof.

          “ Properties ” means such interests in real property and personal property including without limitation, fee interests, interests in ground leases, interests in joint ventures, interests in mortgages, and Debt instruments as the Partnership may hold from time to time.

          “ Qualifying Party ” means (a) an Additional Limited Partner; (b) a Family Member, or a lending institution as the pledgee of a Pledge, who is the transferee in a Permitted Transfer; (c) a Substituted Limited Partner succeeding to all or part of the Limited Partner Interest of (i) an Additional Limited Partner or (ii) a Family Member, or a lending institution who is the pledgee of a Pledge, who is the transferee in a Permitted Transfer; or (d) an LTIP Unitholder with respect to Non-Forfeitable LTIP Units with respect to which the LTIP Equalization Date has occurred.

          “ Qualified REIT Subsidiary ” means any Subsidiary of the General Partner that is a “qualified REIT subsidiary” within the meaning of Section 856(i) of the Code.

          “ Qualified Transferee ” means an “Accredited Investor” as such term is defined in Rule 501 promulgated under the Securities Act.

          “ Redemption ” shall have the meaning set forth in Section 8.6.A .

          “ Regulations ” means the Treasury Regulations promulgated under the Code, as such regulations may be amended from time to time (including corresponding provisions of succeeding regulations).

          “ Regulatory Allocations ” shall have the meaning set forth in Section 6.3.A(viii) .

          “ REIT ” means a real estate investment trust, as defined under Sections 856 through 860 of the Code.

          “ REIT Requirements ” shall have the meaning set forth in Section 5.1 .

          “ REIT Series A Preferred Share ” means a share of 7.375% Series A Cumulative Redeemable Preferred Stock, par value $.01 per share, liquidation preference $25 per share, of the General Partner.

          “ REIT Share ” means a share of common stock, par value $0.01 per share, of the General Partner.

          “ REIT Shares Amount ” means, as of any date, an aggregate number of REIT Shares equal to the number of Tendered Units, as adjusted (x) pursuant to Section 7.5 (in the event the General Partner acquires material assets, other than on behalf of the Partnership) and (y) for stock dividends and distributions, stock splits and subdivisions, reverse stock splits and combinations, distributions of rights, warrants or options, and distributions of evidences of indebtedness or assets relating to assets not received by the General Partner pursuant to a pro rata distribution by the Partnership.

          “ Safe Harbor Election ” has the meaning set forth in Section 4.6.B(2).

          “ Securities Act ” means the Securities Act of 1933, as amended, and the rules and regulations of the Securities and Exchange Commission promulgated thereunder and any successor statute thereto.

          “ Series A Articles Supplementary ” means the Articles Supplementary of the General Partner in connection with its REIT Series A Preferred Shares, as filed with the State Department of Assessments and Taxation of Maryland on January 17, 2007.

          “ Series A Preferred Capital ” means a Capital Account balance equal to the product of (i) the number of Series A Preferred Units then held by the General Partner multiplied by (ii) the sum of $25 plus any accrued and unpaid distributions on each Series A Preferred Unit for all past dividend periods and the current distribution period.

          “ Series A Preferred Unit Distribution Payment Date ” shall have the meaning set forth in Section 1.2.A hereof.

          “ Series A Priority Return ” shall mean an amount equal to 7.375% per annum on the stated value of $25 per Series A Preferred Unit (equivalent to the fixed annual amount of $1.84375 per Series A Preferred Unit), commencing on the date of issuance of such Series A Preferred Unit. For any partial quarterly period, the amount of the Series A Priority Return shall be prorated and computed on the basis of a 360-day year consisting of twelve 30-day months. If following a Change of Control the REIT Series A Preferred Shares are not listed on the New York Stock Exchange, the American Stock Exchange or NASDAQ, the Series A Priority Return shall be increased to 8.375% per annum of the stated value of $25 per Series A Preferred Unit

(equivalent to a fixed annual amount of approximately $2.09375 per Series A Preferred Unit) and the holders of Series A Preferred Units shall be entitled to receive out of funds legally available for that purpose, dividends payable in cash cumulative from, but excluding, the first date on which both the Change of Control has occurred and the REIT Series A Preferred Shares are not so listed at the increased dividend rate for as long as the REIT Series A Preferred Shares are not so listed.

          “ Specified Redemption Date ” means the day of receipt by the General Partner of a Notice of Redemption.

          “ Stock Plan ” means any stock incentive, stock option, stock ownership or employee benefits plan of the General Partner.

          “ Subsidiary ” means, with respect to any Person, any corporation, partnership, limited liability company, joint venture or other entity of which a majority of (i) the voting power of the voting equity securities or (ii) the outstanding equity interests is owned, directly or indirectly, by such Person.

          “ Subsidiary Partnership ” means any partnership or limited liability company that is a Subsidiary of the Partnership.

          “ Substituted Limited Partner ” means a Person who is admitted as a Limited Partner to the Partnership pursuant to Section 11.4 .

          “ Surviving Partnership ” shall have the meaning set forth in Section 11.2.B(2) .

          “ Tax Distributions ” shall have the meaning set forth in Section 4.6.D(4) hereof.

          “ Tax Items ” shall have the meaning set forth in Section 6.4.A .

          “ Tenant ” means any tenant from which the General Partner derives rent either directly or indirectly through partnerships, including the Partnership, or Qualified REIT Subsidiaries.

          “ Tendered Units ” shall have the meaning set forth in Section 8.6.A .

          “ Tendering Partner ” shall have the meaning set forth in Section 8.6.A .

          “ Termination Transaction ” shall have the meaning set forth in Section 11.2.B.

Section 1.2 Rules of Construction

          Unless otherwise indicated, all references herein to “ REIT ,” “ REIT Requirements ,” “ REIT Shares ” and “ REIT Shares Amount ” with respect to the General Partner shall apply only with reference to the Company.

ARTICLE 2.
ORGANIZATIONAL MATTERS

Section 2.1 Organization

          The Partnership is a limited partnership formed pursuant to the provisions of the Act and upon the terms and conditions set forth in this Agreement. Except as expressly provided herein, the rights and obligations of the Partners and the administration and termination of the Partnership shall be governed by the Act. The Partnership Interest of each Partner shall be personal property for all purposes.

Section 2.2 Name

          The name of the Partnership is BioMed Realty, L.P. The Partnership’s business may be conducted under any other name or names deemed advisable by the General Partner, including the name of the General Partner or any Affiliate thereof. The words “Limited Partnership,” “L.P.,” “Ltd.” or similar words or letters shall be included in the Partnership’s name where necessary for the purposes of complying with the laws of any jurisdiction that so requires. The General Partner in its sole and absolute discretion may change the name of the Partnership at any time and from time to time and shall notify the Limited Partners of such change in the next regular communication to the Limited Partners.

Section 2.3 Registered Office and Agent; Principal Office

          The name and address of the registered office and registered agent of the Partnership in the State of Maryland are James J. Hanks, Jr., care of Venable LLP, 1800 Mercantile Bank & Trust Bldg., 2 Hopkins Plaza, Baltimore, MD 21201. The address of the principal office of the Partnership in the State of Maryland is c/o Venable LLP at such address. The principal office of the Partnership is located at 17140 Bernardo Center Drive, Suite 222, San Diego, California 92128, or such other place as the General Partner may from time to time designate by notice to the other Partners. The Partnership may maintain offices at such other place or places within or outside the State of Maryland as the General Partner deems advisable.

Section 2.4 Power of Attorney

     A. Each Limited Partner and each Assignee constitutes and appoints the General Partner, any Liquidator, and authorized officers and attorneys-in-fact of each, and each of those acting singly, in each case with full power of substitution, as its true and lawful agent and attorney-in-fact, with full power and authority in its name, place and stead to:

          (1) execute, swear to, acknowledge, deliver, file and record in the appropriate public offices (a) all certificates, documents and other instruments (including, without limitation, this Agreement and the Certificate and all amendments or restatements thereof) that the General Partner or the Liquidator deems appropriate or necessary to form, qualify or continue the existence or qualification of the Partnership as a limited partnership (or a partnership in which the Limited Partners have limited liability) in the State of Maryland and in all other jurisdictions in which the Partnership

may conduct business or own property; (b) all instruments that the General Partner or any Liquidator deems appropriate or necessary to reflect any amendment, change, modification or restatement of this Agreement in accordance with its terms; (c) all conveyances and other instruments or documents that the General Partner or any Liquidator deems appropriate or necessary to reflect the dissolution and liquidation of the Partnership pursuant to the terms of this Agreement, including, without limitation, a certificate of cancellation; (d) all instruments relating to the admission, withdrawal, removal or substitution of any Partner pursuant to, or other events described in, Articles 11 , 12 or 13 or the Capital Contribution of any Partner; and (e) all certificates, documents and other instruments relating to the determination of the rights, preferences and privileges of Partnership Interests; and

          (2) execute, swear to, acknowledge and file all ballots, consents, approvals, waivers, certificates and other instruments appropriate or necessary, in the sole and absolute discretion of the General Partner or any Liquidator, to make, evidence, give, confirm or ratify any vote, consent, approval, agreement or other action which is made or given by the Partners hereunder or is consistent with the terms of this Agreement or appropriate or necessary, in the sole discretion of the General Partner or any Liquidator, to effectuate the terms or intent of this Agreement.

Nothing contained herein shall be construed as authorizing the General Partner or any Liquidator to amend this Agreement except in accordance with Article 14 or as may be otherwise expressly provided for in this Agreement.

     B. The foregoing power of attorney is hereby declared to be irrevocable and a power coupled with an interest, in recognition of the fact that each of the Partners will be relying upon the power of the General Partner and any Liquidator to act as contemplated by this Agreement in any filing or other action by it on behalf of the Partnership, and it shall survive and not be affected by the subsequent Incapacity of any Limited Partner or Assignee and the transfer of all or any portion of such Limited Partner’s or Assignee’s Partnership Units and shall extend to such Limited Partner’s or Assignee’s heirs, successors, assigns and personal representatives. Each such Limited Partner or Assignee hereby agrees to be bound by any representation made by the General Partner or any Liquidator, acting in good faith pursuant to such power of attorney; and each such Limited Partner or Assignee hereby waives any and all defenses which may be available to contest, negate or disaffirm the action of the General Partner or any Liquidator, taken in good faith under such power of attorney. Each Limited Partner or Assignee shall execute and deliver to the General Partner or any Liquidator, within 15 days after receipt of the General Partner’s or Liquidator’s request therefor, such further designation, powers of attorney and other instruments as the General Partner or the Liquidator, as the case may be, deems necessary to effectuate this Agreement and the purposes of the Partnership.

Section 2.5 Term

     The term of the Partnership commenced on April 30, 2004 and shall continue until December 31, 2104 unless it is dissolved sooner pursuant to the provisions of Article 13 or as otherwise provided by law.

ARTICLE 3.
PURPOSE

Section 3.1 Purpose and Business

          The purpose and nature of the business to be conducted by the Partnership is (i) to conduct any business that may be lawfully conducted by a limited partnership organized pursuant to the Act, (ii) to enter into any partnership, joint venture or other similar arrangement to engage in any business described in the foregoing clause (i) or to own interests in any entity engaged, directly or indirectly, in any such business and (iii) to do anything necessary or incidental to the foregoing, provided , however , that such business shall be limited to and conducted in such a manner as to permit the General Partner at all times to be classified as a REIT for federal income tax purposes, unless the General Partner ceases to qualify as a REIT for reasons other than the conduct of the business of the Partnership. In connection with the foregoing, and without limiting the General Partner’s right in its sole discretion to cease qualifying as a REIT, the Partners acknowledge that the General Partner’s current status as a REIT inures to the benefit of all the Partners and not solely the General Partner.

Section 3.2 Powers

          The Partnership is empowered to do any and all acts and things necessary, appropriate, proper, advisable, incidental to or convenient for the furtherance and accomplishment of the purposes and business described herein and for the protection and benefit of the Partnership, including, without limitation, full power and authority, directly or through its ownership interest in other entities, to enter into, perform and carry out contracts of any kind, borrow money and issue evidences of indebtedness, whether or not secured by mortgage, deed of trust, pledge or other lien, acquire, own, manage, improve and develop real property, and lease, sell, transfer and dispose of real property; provided , however , notwithstanding anything to the contrary in this Agreement, the Partnership shall not take, or refrain from taking, any action which, in the judgment of the General Partner, in its sole and absolute discretion, (i) could adversely affect the ability of the General Partner to continue to qualify as a REIT, (ii) absent the consent of the General Partner, which may be given or withheld in its sole and absolute discretion, could subject the General Partner to any taxes under Section 857 or Section 4981 of the Code, or (iii) could violate any law or regulation of any governmental body or agency having jurisdiction over the General Partner or its securities, unless any such action (or inaction) under the foregoing clauses (i), (ii) or (iii) shall have been specifically consented to by the General Partner in writing.

Section 3.3 Partnership Only for Purposes Specified

          The Partnership shall be a partnership only for the purposes specified in Section 3.1 , and this Agreement shall not be deemed to create a partnership among the Partners with

respect to any activities whatsoever other than the activities within the purposes of the Partnership as specified in Section 3.1 . Except as otherwise provided in this Agreement, no Partner shall have any authority to act for, bind, commit or assume any obligation or responsibility on behalf of the Partnership, its properties or any other Partner. No Partner, in its capacity as a Partner under this Agreement, shall be responsible or liable for any indebtedness or obligation of another Partner, nor shall the Partnership be responsible or liable for any indebtedness or obligation of any Partner, incurred either before or after the execution and delivery of this Agreement by such Partner, except as to those responsibilities, liabilities, indebtedness or obligations incurred pursuant to and as limited by the terms of this Agreement and the Act.

Section 3.4 Representations and Warranties by the Parties

     A. Each Partner that is an individual represents and warrants to each other Partner that (i) such Partner has the legal capacity to enter into this Agreement and perform such Partner’s obligations hereunder, (ii) the consummation of the transactions contemplated by this Agreement to be performed by such Partner will not result in a breach or violation of, or a default under, any agreement by which such Partner or any of such Partner’s property is or are bound, or any statute, regulation, order or other law to which such Partner is subject, (iii) such Partner is a “United States person” within the meaning of Section 7701(a)(30) of the Code, and (iv) this Agreement is binding upon, and enforceable against, such Partner in accordance with its terms.

     B. Each Partner that is not an individual represents and warrants to each other Partner that (i) its execution and delivery of this Agreement and all transactions contemplated by this Agreement to be performed by it have been duly authorized by all necessary action, including without limitation, that of its general partner(s), committee(s), trustee(s), beneficiaries, directors and/or stockholder(s), as the case may be, as required, (ii) the consummation of such transactions shall not result in a breach or violation of, or a default under, its certificate of limited partnership, partnership agreement, trust agreement, limited liability company operating agreement, charter or bylaws, as the case may be, any agreement by which such Partner or any of such Partner’s properties or any of its partners, beneficiaries, trustees or stockholders, as the case may be, is or are bound, or any statute, regulation, order or other law to which such Partner or any of such Partner’s properties or any of its partners, trustees, beneficiaries or stockholders, as the case may be, is or are subject, (iii) such Partner is a “United States person” within the meaning of Section 7701(a)(30) of the Code and (iv) this Agreement is binding upon, and enforceable against, such Partner in accordance with its terms.

     C. Each Partner represents, warrants, and agrees that it has acquired and continues to hold its interest in the Partnership for its own account for investment only and not for the purpose of, or with a view toward, the resale or distribution of all or any part thereof, nor with a view toward selling or otherwise distributing such interest or any part thereof at any particular time or under any predetermined circumstances. Each Partner further represents and warrants that it is a sophisticated investor, able and accustomed to handling sophisticated financial matters for itself, particularly real estate investments, and that it has a sufficiently high net worth that it does not anticipate a need

for the funds it has invested in the Partnership in what it understands to be a highly speculative and illiquid investment. Each Partner represents, warrants and agrees that such Partner is an “accredited investor” (as such term is defined in Rule 501(a) of Regulation D under the Securities Act).

     D. Each Partner acknowledges that (i) the Partnership Units (and any REIT Shares that might be exchanged therefor) have not been registered under the Securities Act and may not be transferred unless they are subsequently registered under the Securities Act or an exemption from such registration is available (it being understood that the Partnership has no intention of so registering the Partnership Units), (ii) a restrictive legend in the form set forth in Exhibit D shall be placed on the certificates representing the Partnership Units, and (iii) a notation shall be made in the appropriate records of the Partnership indicating that the Partnership Units are subject to restrictions on transfer.

     E. Each Limited Partner further represents, warrants, covenants and agrees as follows:

          (1) Except as provided in Exhibit E , at any time such Partner actually or Constructively Owns a 25% or greater capital interest or profits interest in the Partnership, it does not and will not, without the prior written consent of the General Partner, actually own or Constructively Own (a) with respect to any Tenant that is a corporation, any stock of such Tenant, and (b) with respect to any Tenant that is not a corporation, any interests in either the assets or net profits of such Tenant.

          (2) Except as provided in Exhibit F , at any time such Partner actually or Constructively Owns a 25% or greater capital interest or profits interest in the Partnership, it does not, and agrees that it will not without the prior written consent of the General Partner, actually own or Constructively Own, any stock in the General Partner, other than any REIT Shares or other shares of capital stock of the General Partner such Partner may acquire (a) as a result of an exchange of Tendered Units pursuant to Section 8.6 or (b) upon the exercise of options granted or delivery of REIT Shares pursuant to any Stock Plan, in each case subject to the ownership limitations set forth in the General Partner’s Charter.

          (3) Upon request of the General Partner, it will disclose to the General Partner the amount of REIT Shares or other shares of capital stock of the General Partner that it actually owns or Constructively Owns.

          (4) It understands that if, for any reason, (a) the representations, warranties or agreements set forth in E(1) or (2) above are violated, or (b) the Partnership’s actual or Constructive Ownership of REIT Shares or other shares of capital stock of the General Partner violates the limitations set forth in the Charter, then (x) some or all of the Redemption rights of the Partners may become non-exercisable, and (y) some or all of the REIT Shares owned by the Partners may be automatically transferred to a trust for the benefit of a charitable beneficiary, as provided in the Charter.

          (5) Without the consent of the General Partner, which may be given or withheld in its sole discretion, no Partner shall take any action that would cause the Partnership at any time to have more than 100 partners (including as partners those persons indirectly owning an interest in the Partnership through a partnership, limited liability company, S corporation or grantor trust (such entity, a “ flow through entity ”), but only if substantially all of the value of such person’s interest in the flow through entity is attributable to the flow through entity’s interest (direct or indirect) in the Partnership).

     F. The representations and warranties contained in Sections 3.4 shall survive the execution and delivery of this Agreement by each Partner and the dissolution and winding-up of the Partnership.

     G. Each Partner hereby acknowledges that no representations as to potential profit, cash flows, funds from operations or yield, if any, in respect of the Partnership or the General Partner have been made by any Partner or any employee or representative or Affiliate of any Partner, and that projections and any other information, including, without limitation, financial and descriptive information and documentation, which may have been in any manner submitted to such Partner shall not constitute any representation or warranty of any kind or nature, express or implied.

Section 3.5 Certain ERISA Matters

          Each Partner acknowledges that the Partnership is intended to qualify as a “real estate operating company” (as such term is defined in the Plan Asset Regulation). The General Partner may structure the investments in, relationships with and conduct with respect to Properties and any other assets of the Partnership so that the Partnership will be a “real estate operating company” (as such term is defined in the Plan Asset Regulation).

ARTICLE 4.
CAPITAL CONTRIBUTIONS

Section 4.1 Capital Contributions of the Partners

          At the time of their respective execution of this Agreement, the Partners shall make or shall have made Capital Contributions as set forth in Exhibit A to this Agreement. The Partners shall own Partnership Units of the class or series and in the amounts set forth in Exhibit A and shall have a Percentage Interest in the Partnership as set forth in Exhibit A , which Percentage Interest shall be adjusted in Exhibit A from time to time by the General Partner to the extent necessary to reflect accurately exchanges, redemptions, Capital Contributions, the issuance of additional Partnership Units or similar events having an effect on a Partner’s Percentage Interest. Except as required by law, as otherwise provided in Sections 4.3 , 4.4 and 10.5 , or as otherwise agreed to by a Partner and the Partnership, no Partner shall be required or permitted to make any additional Capital Contributions or loans to the Partnership. Unless otherwise specified by the General Partner at the time of the creation of any class of Partnership Interests, the corresponding class or series of capital stock for any Partnership Units issued shall be REIT Shares.

Section 4.2 Loans by Third Parties

          Subject to Section 4.3 , the Partnership may incur Debt, or enter into other similar credit, guarantee, financing or refinancing arrangements for any purpose (including, without limitation, in connection with any further acquisition of Properties) with any Person that is not the General Partner upon such terms as the General Partner determines appropriate; provided that , the Partnership shall not incur any Debt that is recourse to the General Partner, except to the extent otherwise agreed to by the General Partner in its sole discretion.

Section 4.3 Additional Funding and Capital Contributions

     A. General . The General Partner may, at any time and from time to time determine that the Partnership requires additional funds (“ Additional Funds ”) for the acquisition of additional Properties or for such other Partnership purposes as the General Partner may determine. Additional Funds may be raised by the Partnership, at the election of the General Partner, in any manner provided in, and in accordance with, the terms of this Section 4.3 . No Person shall have any preemptive, preferential or similar right or rights to subscribe for or acquire any Partnership Interest, except as set forth in this Section 4.3 .

     B. Issuance of Additional Partnership Interests . The General Partner, in its sole and absolute discretion, may raise all or any portion of the Additional Funds by accepting additional Capital Contributions of cash. The General Partner may also accept additional Capital Contributions of real property or any other non-cash assets. In connection with any such additional Capital Contributions (of cash or property), the General Partner is hereby authorized to cause the Partnership from time to time to issue to Partners (including the General Partner) or other Persons (including, without limitation, in connection with the contribution of property to the Partnership) additional Partnership Units or other Partnership Interests in one or more classes, or one or more series of any of such classes, with such designations, preferences and relative, participating, optional or other special rights, powers, and duties, including rights, powers, and duties senior to then existing Limited Partner Interests, all as shall be determined by the General Partner in its sole and absolute discretion subject to Maryland law, and as set forth by amendment to this Agreement, including without limitation, (i) the allocations of items of Partnership income, gain, loss, deduction, and credit to such class or series of Partnership Interests; (ii) the right of each such class or series of Partnership Interests to share in Partnership distributions; (iii) the rights of each such class or series of Partnership Interests upon dissolution and liquidation of the Partnership; and (iv) the right to vote, including, without limitation, the Limited Partner approval rights set forth in Section 11.2.A ; provided , that no such additional Partnership Units or other Partnership Interests shall be issued to the General Partner unless either (a) (1) the additional Partnership Interests are issued in connection with the grant, award, or issuance of shares of the General Partner pursuant to Section 4.3.C below, which shares have designations, preferences, and other rights (except voting rights) such that the economic interests attributable to such shares are substantially similar to the designations, preferences and other rights of the additional Partnership Interests issued to the General Partner in accordance with this Section 4.3.B , and (2) the General Partner shall make a

Capital Contribution to the Partnership in an amount equal to the net proceeds raised in connection with such issuance, or (b) the additional Partnership Interests are issued to all Partners holding Partnership Interests in the same class in proportion to their respective Percentage Interests in such class. The General Partner’s determination that consideration is adequate shall be conclusive insofar as the adequacy of consideration relates to whether the Partnership Interests are validly issued and paid. In the event that the Partnership issues additional Partnership Interests pursuant to this Section 4.3.B , the General Partner shall make such revisions to this Agreement (including but not limited to the revisions described in Section 5.4 , Section 6.2.C , and Section 8.6 ) as it determines are necessary to reflect the issuance of such additional Partnership Interests. Without limiting the foregoing, the General Partner is expressly authorized to cause the Partnership to issue Partnership Units for no tangible value or for less than fair market value, so long as the General Partner concludes in good faith that such issuance of Partnership Interests is in the best interests of the Partnership.

     C. Issuance of REIT Shares or Other Securities by the General Partner . The General Partner shall not issue any additional REIT Shares, other shares of capital stock of the General Partner or New Securities (other than REIT Shares issued pursuant to Section 8.6 or such shares, stock or securities pursuant to a dividend or distribution (including any stock split) to all of its stockholders or all of its stockholders who hold a particular class of stock of the General Partner) unless (i) the General Partner shall cause the Partnership to issue to the General Partner, Partnership Interests or rights, options, warrants or convertible or exchangeable securities of the Partnership having designations, preferences and other rights, all such that the economic interests thereof are substantially similar to those of the REIT Shares, other shares of capital stock of the General Partner or New Securities issued by the General Partner and (ii) the General Partner shall make a Capital Contribution of the net proceeds from the issuance of such additional REIT Shares, other shares of capital stock or New Securities, as the case may be, and from the exercise of the rights contained in such additional New Securities, as the case may be. Without limiting the foregoing, the General Partner is expressly authorized to issue REIT Shares, other shares of capital stock of the General Partner or New Securities for no tangible value or for less than fair market value, and the General Partner is expressly authorized to cause the Partnership to issue to the General Partner corresponding Partnership Interests, so long as (x) the General Partner concludes in good faith that such issuance of Partnership Interests is in the interests of the Partnership; and (y) the General Partner contributes all proceeds, if any, from such issuance and exercise to the Partnership.

          In connection with the General Partner’s initial public offering of REIT Shares, any other issuance of REIT Shares, other capital stock of the General Partner or New Securities, the General Partner shall contribute to the Partnership, any net proceeds raised in connection with such issuance; provided , that the General Partner may use a portion of the net proceeds from any offering to acquire Partnership Units or other assets (provided such other assets are contributed to the Partnership pursuant to the terms of this Agreement; and provided further that if the net proceeds actually received by the General Partner are less than the gross proceeds of such issuance as a result of any underwriter’s discount or other expenses paid or incurred in connection with such issuance then, except to the extent such net proceeds are used to acquire

Partnership Units, the General Partner shall be deemed to have made a Capital Contribution to the Partnership in the amount equal to the sum of the net proceeds of such issuance plus the amount of such underwriter’s discount and other expenses paid by the General Partner (which discount and expense shall be treated as an expense for the benefit of the Partnership for purposes of Section 7.4 )). In the case of issuances of REIT Shares, other capital stock of the General Partner or New Securities pursuant to any Stock Plan at a discount from fair market value or for no value, the amount of such discount representing compensation to the employee, as determined by the General Partner, shall be treated as an expense for the benefit of the Partnership for purposes of Section 7.4 and, as a result, the General Partner shall be deemed to have made a Capital Contribution to the Partnership in an amount equal to the sum of any net proceeds of such issuance plus the amount of such expense.

     D. Percentage Interest Adjustments in the Case of Capital Contributions for Partnership Units . Upon the acceptance of additional Capital Contributions in exchange for any class or series of Partnership Units, the Percentage Interest in such class or series of Partnership Units shall be equal to a fraction, the numerator of which is equal to the amount of cash and the Agreed Value of the Property contributed as of the time such additional Capital Contributions are made (an “ Adjustment Date ”) and the denominator of which is equal to the sum of (i) the Deemed Value of the Partnership Interests of such class or series (computed as of the Business Day immediately preceding the Adjustment Date) and (ii) the aggregate Agreed Value of additional Capital Contributions contributed by all Partners and/or third parties to the Partnership on such Adjustment Date in such class or series of Partnership Interests. The Percentage Interest of each other Partner holding Partnership Interests of such class or series not making a full pro rata Capital Contribution shall be adjusted to equal a fraction, the numerator of which is equal to the sum of (i) the Deemed Partnership Interest Value of such Limited Partner in respect of such class or series (computed as of the Business Day immediately preceding the Adjustment Date) and (ii) the Agreed Value of additional Capital Contributions, if any, made by such Partner to the Partnership in such class or series of Partnership Interests as of such Adjustment Date, and the denominator of which is equal to the sum of (i) the Deemed Value of the Partnership Interests of such class or series (computed as of the Business Day immediately preceding the Adjustment Date), plus (ii) the aggregate Agreed Value of additional Capital Contributions contributed by all Partners and/or third parties to the Partnership on such Adjustment Date in such class or series. Provided, however, solely for purposes of calculating a Partner’s Percentage Interest pursuant to this Section 4.3.D , (i) in the case of cash Capital Contributions by the General Partner funded by an offering of REIT Shares or other shares of capital stock of the General Partner and (ii) in the case of the contribution of properties by the General Partner which were acquired by the General Partner in exchange for REIT Shares or other shares of capital stock of the General Partner immediately prior to such contribution, the General Partner shall be issued a number of Partnership Units equal and corresponding to the number of such shares issued by the General Partner in exchange for such cash or Properties, the Partnership Units held by the other Partners shall not be adjusted, and the Partners’ Percentage Interests shall be adjusted accordingly. The General Partner shall promptly give each Partner written notice of its Percentage Interest, as adjusted.

Section 4.4 Other Contribution Provisions

          In the event that any Partner is admitted to the Partnership and is given (or is treated as having received) a Capital Account at the time of admission in exchange for services rendered to the Partnership, such transaction shall be treated by the Partnership and the affected Partner as if the Partnership had compensated such Partner in cash, and the Partner had contributed such cash to the capital of the Partnership. In addition, with the consent of the General Partner, in its sole discretion, one or more Limited Partners may enter into agreements with the Partnership, in the form of a guarantee or contribution agreement, which have the effect of providing a guarantee of certain obligations of the Partnership.

Section 4.5 No Preemptive Rights

          Except to the extent expressly granted by the Partnership pursuant to another agreement, no Person shall have any preemptive, preferential or other similar right with respect to (i) providing funds to the Partnership or (ii) issuance or sale of any Partnership Units or other Partnership Interests.

Section 4.6 LTIP Units.

     A. Grant of LTIP Units. The General Partner may from time to time, but not less frequently than once in each calendar year beginning with 2007 unless it otherwise determines, cause the Partnership to grant LTIP Units to any Person rendering services to the Partnership in each year for services rendered by such Person to the Partnership, in its capacity as a Partner, or in anticipation of becoming a Partner, and admit any such Person as a Limited Partner. Subject to the following provisions of this Section and the special provisions of Sections 4.8, 6.3.B and 14.3, LTIP Units shall be treated as Partnership Units, with all of the rights, privileges and obligations attendant thereto. For purposes of computing the Partners’ Percentage Interests, LTIP Units shall be treated as Partnership Units. Exhibit A sets forth the initial grants of LTIP Units issued as of the date hereof. The General Partner may grant LTIP Units to any Person at any time, in its sole and absolute discretion.

     B. Status of LTIP Units.

          (1) LTIP Units shall be fully vested when granted to a Person, but shall be subject to forfeiture as provided in this Section 4.6. The value of an LTIP Unit upon issuance (and the Economic Capital Account Balance of an LTIP Unitholder with respect to such LTIP Units upon issuance) shall be zero, the amount of distributions such LTIP Unit would produce for an LTIP Unitholder if the Partnership’s assets were sold for their Gross Asset Value as of such issuance date (it being agreed that apart from applicable distributions of Available Cash from operations, an LTIP Unit may only share in distributions of sale and liquidation proceeds from a Partnership asset to the extent of income allocated to the holder thereof under Section 6.3.B that is attributable to the appreciation in value of such asset after such LTIP Unit’s grant date, all as provided in Sections 5.1 and 6.3.B).

          (2) Safe Harbor Election and Forfeiture Allocations:

               (a) The Partners agree that the General Partner is authorized and directed to make an election, on behalf of itself and of all Partners, to have the “Safe Harbor” of Section 3.03 of IRS Notice 2005-43 (or the corresponding provision in any Revenue Procedure or regulation issued in execution of the provisions of such Notice) (the “Safe Harbor”) apply irrevocably with respect to all LTIP Units transferred in connection with the performance of services by a Partner in a partner capacity, or in anticipation of becoming a Partner (such election, the “Safe Harbor Election”). The Safe Harbor Election shall be effective as of the date hereof. The Partnership and each Partner agrees to comply with all requirements of the Safe Harbor with respect to all interests in the Partnership transferred in connection with the performance of services by a Partner in a partner capacity or in anticipation of becoming a Partner, whether such Partner was admitted as a Partner or as the transferee of a previous Partner. The General Partner shall cause the Partnership to comply with all record-keeping requirements and other administrative requirements with respect to the Safe Harbor as shall be required by proposed or final regulations relating thereto.

               (b) In connection with the Safe Harbor Election, the Partners agree that (I) each LTIP Unit issued hereunder is a “Safe Harbor Partnership Interest” within the meaning of section 3.02 of IRS Notice 2005-43 (or the corresponding provision in any Revenue Procedure or regulation issued in relation to the provisions of such Notice or successor pronouncement) representing a profits interest received for services rendered or to be rendered to or for the benefit of the Partnership by the LTIP Unitholder in his or her capacity as a Partner or in anticipation of becoming a Partner, and (II) the fair market value of the Safe Harbor Partnership Interest upon receipt by the LTIP Unitholder as of the date of issuance is zero, representing the liquidation value of such interest upon receipt (with such valuation being consented to and hereby approved by all Partners).

               (c) Each Partner hereby agrees (I) to comply with all requirements of the Safe Harbor Election with respect to each LTIP Unitholder’s Safe Harbor Partnership Interest, and (II) that to the extent that such profits interest is forfeited after the date hereof and to the extent that allocations of income have been made to LTIP Unitholder with respect thereto and have not been matched with corresponding amounts of distributions with respect thereto, the Partnership shall make special forfeiture allocations of gross items of deduction or loss (including, as may be permitted by or under Treasury Regulations to be adopted, notional items of deduction or loss) in accordance with the Treasury Regulations to be adopted under Sections 704(b) and 83 of the Code.

               (d) The General Partner shall file or cause the Partnership to file all returns, reports and other documentation as may be required, as reasonably determined by the General Partner, to perfect and maintain the Safe Harbor Election with respect to transfers of each LTIP Unitholder’s Safe Harbor Partnership Interest.

               (e) The General Partner is hereby authorized, directed and empowered, without further vote or action of the Partners, to amend the Agreement as necessary to comply with the Safe Harbor requirements in order to provide for a Safe

Harbor Election and the ability to maintain the same, and shall have the authority to execute any such amendment by and on behalf of each Partner pursuant to the power of attorney granted by this Agreement. Any undertaking by the Partners necessary to enable or preserve a Safe Harbor Election may be reflected in such amendments and, to the extent so reflected, shall be binding on each Partner. The General Partner and the Partnership hereby (1) approve the adoption of the BioMed Realty Trust, Inc. and BioMed Realty L.P. 2004 Incentive Award Plan, (2) approve the filing of Section 83(b) elections for each employee granted LTIP Units and (3) ratify the form of LTIP Forfeiture Agreement and all of the exhibits attached thereto. Each employee granted LTIP Units shall file a Section 83(b) election.

               (f) Each Partner agrees to cooperate with the General Partner to perfect and maintain any Safe Harbor Election, and to timely execute and deliver any documentation with respect thereto reasonably requested by the General Partner, at the expense of the Company.

               (g) No Transfer of any interest in the Partnership by a Partner shall be effective unless prior to such Transfer, the assignee or intended recipient of such interest shall have agreed in writing to be bound by the provisions of this Section 4.6.B(2), in a form reasonably satisfactory to the General Partner.

          (3) No Conversion to Partnership Units Required. Subject to the tax allocations required to be made to an LTIP Unitholder pursuant to Section 6.4 following a Book-up Event, an LTIP Unit automatically is treated as a Partnership Unit when the LTIP Equalization Date has occurred under Section 6.3.B (i.e., when an LTIP Unitholder has been allocated book gain upon a Book-up Event pursuant to Section 6.3.B or allocated actual income from the sale of Partnership assets in an amount necessary to cause the LTIP Unitholder’s book Capital Account with respect to such LTIP Unit to equal the Partnership Unit Economic Balance per Unit), but only Non-Forfeitable LTIP Units may be the subject of a Redemption election by an LTIP Unitholder. LTIP Units may not be sold within two (2) years of the date of grant of such LTIP Units without the prior written consent of the General Partner, which may be withheld in the General Partner’s sole and absolute discretion . Until the LTIP Equalization Date has occurred with respect to an LTIP Unit, (i) such LTIP Unit may not be the subject of a Redemption election by the LTIP Unitholder, and (ii) such LTIP Unit will participate like a Partnership Unit in distributions of Available Cash from operations and only participate in sale and liquidation proceeds with respect to a Partnership asset to the extent of income allocated to the holder thereof under Section 6.3.B that is attributable to the appreciation in value of such asset after the issuance date of such LTIP Unit, all as provided in Sections 5.1 and 6.3.B.

          (4) Adjustments to LTIP Units.

               (a) If an Adjustment Event (as defined below) occurs, then the General Partner shall make a corresponding adjustment to the LTIP Units (to maintain a one-for-one conversion and economic equivalence ratio between Partnership Units and LTIP Units, upon the LTIP Equalization Date occurring under Section 6.3.B).

               (b) The following shall be “Adjustment Events”: (A) the Partnership makes a distribution on all outstanding Partnership Units in Partnership Units, (B) the Partnership subdivides the outstanding Partnership Units into a greater number of units or combines the outstanding Partnership Units into a smaller number of units, or (C) the Partnership issues any Partnership Units in exchange for its outstanding Partnership Units by way of a reclassification or recapitalization of its Partnership Units. If more than one Adjustment Event occurs, the adjustment to the LTIP Units need be made only once using a single formula that takes into account each and every Adjustment Event as if all Adjustment Events occurred simultaneously.

               (c) For the avoidance of doubt, the following shall not be Adjustment Events: (x) the issuance of Partnership Units in a financing, reorganization, acquisition or other similar business transaction, (y) the issuance of Partnership Units pursuant to any employee benefit or compensation plan or distribution reinvestment plan, or (z) the issuance of any Partnership Units to the General Partner in respect of a capital contribution to the Partnership of proceeds from the sale of securities by the General Partner.

               (d) If the Partnership takes an action affecting the Partnership Units other than actions specifically described above as “Adjustment Events” and in the good faith discretion of the General Partner such action would require an adjustment to the LTIP Units to maintain the one-to-one correspondence described above, the General Partner shall make such adjustment to the LTIP Units, to the extent permitted by law, in such manner and at such time as the General Partner, in its good faith discretion, may determine to be appropriate under the circumstances.

               (e) If an adjustment is made to the LTIP Units as herein provided, the Partnership shall promptly file in the books and records of the Partnership an officer’s certificate setting forth such adjustment and a brief statement of the facts requiring such adjustment, which certificate shall be conclusive evidence of the correctness of such adjustment absent manifest error. Promptly after filing of such certificate, the Partnership shall mail a notice to each LTIP Unitholder setting forth the adjustment to his or her LTIP Units and the effective date of such adjustment.

     C. Priority. Upon the LTIP Equalization Date occurring under Section 6.3.B, the LTIP Units shall rank pari passu with the Partnership Units as to the payment of regular and special periodic or other distributions and distributions upon sale of assets, liquidation, dissolution or winding up. As to the payment of distributions and as to distribution of assets upon sale, liquidation, dissolution or winding up, any class or series of Partnership Units or Partnership Interests which by its terms specifies that it shall rank junior to, on a parity with, or senior to the Partnership Units shall also rank junior to, or pari passu with, or senior to, as the case may be, the LTIP Units.

     D. Special Provisions. LTIP Units shall be subject to the following special provisions:

          (1) LTIP Forfeiture Agreements and Transferability. LTIP Units may, in the sole discretion of the General Partner, be issued subject to forfeiture and additional restrictions on transfer pursuant to the terms of an LTIP Forfeiture Agreement. The terms of an LTIP Forfeiture Agreement may be modified by the General Partner from time to time in its sole discretion, subject to any restrictions on amendment imposed by the relevant LTIP Forfeiture Agreement, if applicable. LTIP Units that no longer are subject to forfeiture under the terms of an LTIP Forfeiture Agreement are referred to as “Non-Forfeitable LTIP Units”; all other LTIP Units shall be treated as “Forfeitable LTIP Units.” Subject to the terms of any LTIP Forfeiture Agreement and upon the LTIP Equalization Date occurring under Section 6.3.B, an LTIP Unitholder shall be entitled to transfer or redeem his or her Non-Forfeitable LTIP Units to the same extent, and subject to the same restrictions as holders of Partnership Units are entitled to transfer their Partnership Units pursuant to Article 11.

          (2) Forfeiture. Unless otherwise specified in the LTIP Forfeiture Agreement, upon the occurrence of any event specified in an LTIP Forfeiture Agreement as resulting in either the right of the Partnership or the General Partner to repurchase LTIP Units at a specified purchase price or some other forfeiture of any LTIP Units, then if the Partnership or the General Partner exercises such right to repurchase or forfeiture in accordance with the applicable LTIP Forfeiture Agreement, then the relevant LTIP Units shall immediately, and without any further action, be treated as cancelled and no longer outstanding for any purpose. Unless otherwise specified in the LTIP Forfeiture Agreement, no consideration or other payment shall be due with respect to any LTIP Units that have been forfeited, other than any distributions declared with respect to a Partnership Record Date prior to the effective date of the forfeiture in which such LTIP Units are permitted to share. In connection with any repurchase or forfeiture of LTIP Units, the balance of the portion of the Capital Account of the Holder that is attributable to all of his or her LTIP Units shall be reduced by the amount, if any, by which it exceeds the target balance contemplated by Section 6.3.B, calculated with respect to the Holder’s remaining LTIP Units, if any, through the use of forfeiture allocations under Section 4.6.B(2)(C).

          (3) Allocations. LTIP Units shall generally be treated as Partnership Units for purposes of Article 6, but shall also receive certain special allocations of income or gain under Sections 6.3 and 6.4.

          (4) Redemption. The Redemption Right provided to Limited Partners under Section 8.6 shall not apply with respect to LTIP Units unless and until the LTIP Equalization Date occurs under Section 6.3.B, and then only with respect to LTIP Units that are Non-Forfeitable LTIP Units.

          (5) Legend. Any certificate evidencing an LTIP Unit shall bear an appropriate legend indicating that additional terms, conditions and restrictions on transfer, including without limitation any LTIP Forfeiture Agreement, apply to the LTIP Unit.

          (6) Voting. LTIP Units shall have the voting rights provided in Section 14.3.

          (7) LTIP Unit Grants. Exhibit A shows the LTIP Units granted as of the date hereof under the BioMed Realty Trust, Inc. and BioMed Realty L.P. 2004 Incentive Award Plan. The forfeiture provisions for LTIP Units shall expire ratably one-third on each 12-month anniversary of the grant of such LTIP Units unless otherwise determined by the General Partner prior to the grant of such LTIP Units.

          (8) Tax Distributions to LTIP Unitholders. To the extent distributions to an LTIP Unitholder are insufficient to accomplish the following, the General Partner shall cause the Partnership to make periodic tax distributions to each LTIP Unitholder on or before the date estimated taxes would be due to be paid by such LTIP Unitholder on the income or gain allocated to such LTIP Unitholder by the Partnership with respect to such LTIP Unitholder’s LTIP Units (“Tax Distributions”). The amount of Tax Distributions to be made by the Partnership to each LTIP Unitholder shall be an advance against distributions otherwise distributable to such LTIP Unitholder (including amounts payable on a redemption thereof) and shall equal the excess of (1) the sum of the combined, cumulative federal and state income tax liability that such LTIP Unitholder would recognize by reason of allocations of taxable income with respect to such LTIP Units if such LTIP Unitholder were an individual residing in California who was subject to the maximum federal and state income tax rates on the income recognized, computed by taking into account (a) the deductibility of state taxes for federal income tax purposes, (b) the character of the income recognized as capital or ordinary, (c) the impact of Section 470 of the Code on the ability of the Partnership or the LTIP Unitholders to utilize losses or deductions, and (d) applicable holding periods (but not taking into account any of the LTIP Unitholder’s actual tax attributes), over (2) the cumulative distributions (including Tax Distributions) theretofore made (or currently being made) to such LTIP Unitholder by the Partnership with respect to such LTIP Units.

Section 4.7 No Interest; No Return .

          No Partner shall be entitled to interest on its Capital Contribution or on such Partner’s Capital Account. Except as provided herein or by law, no Partner shall have any right to demand or receive the return of its Capital Contribution from the Partnership.

Section 4.8 LTIP Units Characterized as Partnership Units .

     A. Non-Forfeitable LTIP Units shall be treated as Partnership Units for all purposes from and after the occurrence of the LTIP Equalization Date under Section 6.3.B, and special allocations of income or gain under Section 4.6.B(2)(C) and Section 6.3, and tax allocations required to be made under Section 6.4 after a Book-up Event, shall continue to be made to the Non-Forfeitable LTIP Units to the extent required by this Agreement. Forfeitable LTIP Units shall remain subject to the applicable forfeitability provisions from the date hereof. All LTIP Units shall be subject to the two (2) year holding period prior to sale under Section 4.6.B(3).

     B. Until the LTIP Equalization Date has occurred with respect to such LTIP Units, the provisions of Sections 4.6.B(1) and (3) shall apply with respect to such LTIP Units.

ARTICLE 5.
DISTRIBUTIONS

Section 5.1 Requirement and Characterization of Distributions

          The General Partner shall cause the Partnership to distribute quarterly all, or such portion as the General Partner may in its discretion determine, Available Cash generated by the Partnership to the Partners who are Partners on the applicable Partnership Record Date with respect to such distribution, (1) first, with respect to any class or series of Partnership Interests that are entitled to any preference in distributions, in accordance with the rights of such class or series of Partnership Interests (and within such class or series, pro rata in proportion to the respective Percentage Interests on the applicable Partnership Record Date), and (2) second, with respect to any class or series of Partnership Interests that are not entitled to any preference in distributions, pro rata to each such class or series in accordance with the terms of such class or series to the Partners who are Partners of such class or series on the Partnership Record Date with respect to such distribution (and within each such class or series, pro rata in proportion to the respective Percentage Interests on such Partnership Record Date). Unless otherwise expressly provided for herein or in an agreement, if any, entered into in connection with the creation of a new class or series of Partnership Interests created in accordance with Article 4 , no Partnership Interest shall be entitled to a distribution in preference to any other Partnership Interest. The General Partner shall take such reasonable efforts, as determined by it in its sole and absolute discretion and consistent with its qualification as a REIT, to cause the Partnership to distribute sufficient amounts to enable the General Partner, for so long as the General Partner has determined to qualify as a REIT, to pay stockholder dividends that will (a) satisfy the requirements for qualifying as a REIT under the Code and Regulations (“REIT Requirements”), and (b) except to the extent otherwise determined by the General Partner, avoid the imposition of any federal income or excise tax liability on the General Partner, except to the extent that a distribution pursuant to clause (b) would prevent the Partnership from making a distribution to the Holders of Series A Preferred Units in accordance with Section 16.2 . An LTIP Unitholder shall be entitled to share in all distributions of Available Cash as if each LTIP Unit were a Partnership Unit, but until the LTIP Equalization Date has occurred with respect to an LTIP Unit, such LTIP Unit may only participate in sale and liquidation proceeds from an asset to the

extent of income allocated to the holder thereof under Section 6.3.B that is attributable to the appreciation in value of such asset after the LTIP Un