2ND AMENDED AND RESTATED AGREEMENT

Exhibit 10.26

SECOND AMENDED AND RESTATED

AGREEMENT OF LIMITED PARTNERSHIP

OF

HINES-SUMISEI US CORE OFFICE PROPERTIES LP

September 20, 2004

[Schedule Amended October 4,2004]

TABLE OF CONTENTS

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List of Schedules:

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SECOND AMENDED AND RESTATED

AGREEMENT OF LIMITED PARTNERSHIP

OF

HINES-SUMISEI US CORE OFFICE PROPERTIES LP

          This SECOND AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF HINES-SUMISEI US CORE OFFICE PROPERTIES LP, a Delaware limited partnership (together with its successors, the “ Partnership ”), is entered into as of September 20, 2004 by and among Hines-Sumisei U.S. Core Office Trust, a Maryland real estate investment trust (the “ Trust ” and “ General Partner ”), as the general partner of the Partnership, and the Persons identified as Limited Partners on Schedule 2.1, as limited partners of the Partnership.

Recitals

          WHEREAS, Hines US Core Office Capital LLC, a Delaware limited liability company (the “ Original GP ”), and the Hines Limited Partner entered into that certain Agreement of Limited Partnership of the Partnership, dated as of March 5, 2003 (the “ Original Agreement ”);

          WHEREAS, Hines US Core Office Capital LLC, a Delaware limited liability company (the “ Original GP ”), and Hines US Core Office Capital Associates Limited Partnership, a Texas limited partnership (the “ Hines Limited Partner ”), entered into that certain Agreement of Limited Partnership of the Partnership, dated as of March 5, 2003 (the “ Original Agreement ”);

          WHEREAS, the Original Agreement was amended and restated as provided in the Amended and Restated Agreement of Limited Partnership of the Partnership, dated May 6, 2004 (the “ First Restated Agreement ”), and, in connection therewith, Hines Interests Limited Partnership, a Delaware limited partnership (together with its successors, “ Hines ”), and Sumitomo Life Realty (N.Y.), Inc., a New York corporation (“ SLR ”), were admitted as Limited Partners;

          WHEREAS, immediately prior to the execution and delivery of the First Restated Agreement, the Original GP transferred all of its interest in the Partnership, including its interest as general partner, to the Trust and withdrew from the Partnership, and the Trust was admitted as the general partner of the Partnership; and

          WHEREAS, the General Partner desires to amend and restate the First Restated Agreement in its entirety as provided herein as permitted by Section 13.3 of the First Restated Agreement.

          NOW, THEREFORE, in consideration of the premises, the terms and conditions set forth herein, the mutual benefits to be gained by the performance thereof and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the

General Partner and the Limited Partners hereby amend and restate the First Restated Agreement in its entirety as follows:

ARTICLE I

          SECTION 1.1 Definitions. As used in this Agreement (including in the preamble and recitals), the terms set forth below have the meanings indicated.

          “ Act ”: The Delaware Revised Uniform Limited Partnership Act, as amended from time to time, and any successor statute.

          “ Acquisition Fee ”: As defined in Section 7.3(a).

          “ Adjusted Capital Account ”: At any time, the then balance in the Capital Account of a Partner, after giving effect to the following adjustments:

     (i) add to such Capital Account any amounts that such Partner is obligated to restore under any provision of this Agreement or such Partners’ Subscription Agreement or is deemed obligated to restore as described in the penultimate sentences of Regulations Section 1.704-2(g)(l) and Regulations Section 1.704-2(i)(5), or any successor provisions; and

     (ii) subtract from such Capital Account the items described in Regulations Sections 1.704-l(b)(2)(ii)(d)(4), (5) and (6).

          “ Adjusted Capital Account Deficit ”: With respect to any Partner, the deficit balance, if any, in that Partner’s Adjusted Capital Account.

          “ Advisory Agreement ”: The Amended and Restated Advisory Agreement, dated as of April 1, 2004, by and among the Partnership, the General Partner, the Fund Partnership, the Fund General Partner, SLR and such other Fund Entities as may become party thereto as contemplated by Section 5.7 of the Fund Partnership Agreement.

          “ Advisory Committee ”: As defined in the Fund Partnership Agreement.

          “ Affiliate ”: With respect to any Person, a Person which, directly or indirectly, Controls, is Controlled by or is under common Control with such Person.

          “ Aggregate Debt Limit ”: As defined in Section 3.6(a)(i)(A).

          “ Agreement ”: This Second Amended and Restated Agreement of Limited Partnership of the Partnership, together with all Schedules and Exhibits hereto, as of the date hereof and as each may be amended from time to time.

          “ Applicable Percentage ”: As defined in Section 5.9(c)(i).

          “ Appraiser ”: As defined in the Fund Partnership Agreement.

          “ Approved Agreement ”: As defined in the Fund Partnership Agreement.

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          “ Asset Management Fee ”: As defined in Section 7.2(a).

          “ Asset Management Fee Base ”: As defined in Section 7.2(a).

          “ Board of Trustees ”: As defined in the Declaration of Trust.

          “ Business Day ”: Any day other than a Saturday or Sunday, that is neither a legal holiday nor a day on which banking institutions in New York City are authorized or required by law, regulation or executive order to close.

          “ Capital Account ”: As defined in Section 8.1.

          “ Capital Call Notice ”: As defined in Section 3.2(a).

          “ Capital Calls ”: As defined in Section 3.2(a).

          “ Capital Cash Flow ”: As defined in Section 9.2.

          “ Capital Commitment ”: As defined in Section 3.2(a).

          “ Capital Contribution ”: With respect to any Partner, any contribution to the capital of the Partnership by such Partner in accordance with this Agreement.

          “ Capital Transaction Gain or Loss ”: Any Profits or Losses described in paragraphs (iii), (iv) and (vi) of the definition of Profits and Losses contained in this Section 1.1.

          “ Cash Amount ”: An amount of cash equal to the value of the REIT Shares Amount based upon the Current Unit Value (and Current Participation Interest Value as applicable) on the date of receipt by the General Partner of a Notice of Redemption.

          “ Cash Needs ”: Any cash needs or requirements of whatever kind of the Partnership for which sufficient funds are not available from investment income or from reserves held by the Partnership, including (i) the cost of acquiring Investments or paying costs and expenses related thereto, (ii) any operating expenses related to any Property, (iii) debt service (including the repayment of principal and the payment of interest and fees ), (iv) any other Partnership Expenses, and (v) the cost of redeeming Partnership Interests in accordance with this Agreement.

          “ CBD ”: As defined in Section 5.1(b)(i).

          “ Certificate ”: As defined in Section 2.1.

          “ Class A Major Investor ”: An Unaffiliated Limited Partner with an aggregate Capital Commitment of at least $300 million.

          “ Class B Major Investor ” An Unaffiliated Limited Partner with an aggregate Capital Commitment of at least $150 million, but less than $300 million.

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          “ Class C Major Investor ” An Unaffiliated Limited Partner with an aggregate Capital Commitment of at least $75 million, but less than $150 million.

          “ Class D Major Investor ” An Unaffiliated Limited Partner with an aggregate Capital Commitment of at least $50 million, but less than $75 million.

          “ Code ”: The Internal Revenue Code of 1986, as amended as of the date hereof and as the same may be amended from time to time, and any successor statute.

          “ Committed Capital ”: (i) As to any Partner, the sum of (A) Partnership’s total equity capital multiplied by a fraction, the numerator of which is the total number of OP Units held by such Partner and the denominator of which is the total number of OP Units outstanding plus, prior to the termination of the Investment Period, (B) the Unfunded Commitment of such Partner, and (ii) as to the Partnership, the aggregate of the Committed Capital of all Partners.

          “ Constituent Documents ”: With respect to any Entity, its constituent, governing or organizational documents, including (a) in the case of a limited partnership, its certificate of limited partnership and its limited partnership agreement, (b) in the case of a limited liability company, its articles or certificate of formation and its operating agreement or limited liability company agreement, (c) in the case of a corporation, its articles or certificate of incorporation and its bylaws and (d) in the case of a trust, its declaration of trust and bylaws.

          “ Control ”: With respect to any Person, the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of such Person, whether through the ownership of voting securities, by contract or otherwise.

          “ Contributing Partner ”: As defined in Section 3.7(b).

          “ Current Market Value ”: As defined in Section 5.9(b)(i).

          “ Current Participation Interest Value ”: As defined in Section 5.9(b)(iii).

          “ Current Total Equity Value ”: As defined in Section 5.9(b)(ii).

          “ Current Unit Value ”: As defined in Section 5.9(b)(iv).

          “ Declaration of Trust ”: The Amended and Restated Declaration of Trust of the Trust, as in effect on the date hereof and as the same may be amended from time to time hereafter.

          “ Defaulting Limited Partner ”: As defined in Section 10.6(b).

          “ Default Rate ”: The rate of interest per annum equal to the lesser of (i) the Prime Rate plus four percent and (ii) the highest rate permitted by applicable law.

          “ Depreciation ”: For any Fiscal Year or portion thereof, an amount equal to the depreciation, amortization or other cost recovery deduction allowable with respect to an asset for such period for federal income tax purposes, except that if the Gross Asset Value of an asset

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differs from its adjusted basis for federal income tax purposes at the beginning of such period, Depreciation shall be an amount that bears the same relationship to such beginning Gross Asset Value as the depreciation, amortization or cost recovery deduction in such period for federal income tax purposes bears to the beginning adjusted tax basis; provided however, that if the adjusted basis for federal income tax purposes of an asset at the beginning of such period is zero, Depreciation shall be determined with reference to such beginning Gross Asset Value using any reasonable method selected by the General Partner.

          “ Entity ”: Any corporation, partnership, limited partnership, limited liability company, trust, association, joint stock company or other legal entity.

          “ ERISA ”: The Employee Retirement Income Security Act of 1974, as amended.

          “ Event of Withdrawal ”: As defined in Section 12.1 (a).

          “ Exchange Date ”: As defined in Section 3.8(e).

          “ Fees ”: Asset Management Fees and Acquisition Fees.

          “ Feeder Entity ”: As defined in Section 2.10.

          “ First Restated Agreement ”: As defined in the Recitals of this Agreement.

          “ Fiscal Quarter ”: As defined in Section 2.8.

          “ Fiscal Year ”: As defined in Section 2.8.

          “ Fund ”: As defined in the Fund Partnership Agreement.

          “ Fund Entity ”: As defined in the Fund Partnership Agreement.

          “ Fund General Partner ”: (i) Prior to the admission of the Non-Managing General Partner (as defined in the Fund Partnership Agreement) to the Fund Partnership, the “General Partner” as such term is defined in the Fund Partnership Agreement, and (ii) following the admission of the Non-Managing General Partner to the Fund Partnership, the “Managing General Partner” as such term is defined in the Fund Partnership Agreement.

          “ Fund Interests ”: All interests in the Partnership held by Fund Investors, directly through the ownership of OP Units, and indirectly through the ownership of interests in the Trust or the Fund Partnership.

          “ Fund Investor ”: As defined in the Fund Partnership Agreement.

          “ Fund Partnership ”: Hines-Sumisei U.S. Core Office Fund, L.P., a Delaware limited partnership.

          “ Fund Partnership Agreement ”: The Fourth Amended and Restated Agreement of Limited Partnership, dated as of August 11, 2004, of the Fund Partnership.

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          “ Funded Commitment ”: As defined in Section 3.2(a).

          “ GAAP ”: Generally accepted accounting principles in the United States, consistently applied.

          “ GECC ”: General Electric Capital Corporation, and its successors.

          “ General Partner ”: The Trust, in its capacity as general partner of the Partnership, and its successors, and any Person hereafter admitted as general partner of the Partnership in accordance with the terms of this Agreement.

           GM Investor Rights Agreement ”: The Amended and Restated Investor Rights Agreement, dated as of December 23, 2003, among Hines, the Fund Partnership, NY Trust, General Motors Investment Management Corporation and the other Persons party thereto.

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

     (i) 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 General Partner and agreed to by the Contributing Partner;

     (ii) The Gross Asset Value of all Partnership assets shall be adjusted to equal their respective gross fair market values, as determined by the General Partner, (which determination shall be based upon, and consistent with, the most recent Current Market Values), as of the following times: (a) the acquisition of an additional interest in the Partnership by any new or existing Partner in exchange for more than a de minimis Capital Contribution; (b) 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; (c) the liquidation of the Partnership within the meaning of Regulations Section 1.704-1 (b)(2)(ii)(g); and (d) upon the occurrence of any other event for which such an adjustment is permitted under the Regulations; provided however, that adjustments pursuant to clauses (a), (b) and (d) above shall be made only if the General Partner reasonably determines that such adjustments are necessary or appropriate to reflect the relative economic interests of the Partners in the Partnership;

     (iii) The Gross Asset Value of any Partnership asset distributed to any Partner shall be adjusted to equal the gross fair market value of such asset on the date of distribution as determined by the General Partner (which determination shall be based upon, and consistent with, the most recent Current Market Values); and

     (iv) The Gross Asset Value 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-l(b)(2)(iv)(m) and paragraph (vi) of the definition of

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Profits and Losses and Section 8.6(g); provided, however, that Gross Asset Value shall not be adjusted pursuant to this paragraph (iv) to the extent the General Partner determines that an adjustment pursuant to paragraph (ii) above is necessary or appropriate in connection with a transaction that would otherwise result in an adjustment pursuant to this paragraph (iv).

          If the Gross Asset Value of an asset has been determined or adjusted pursuant to paragraphs (i), (ii) or (iv) above, such Gross Asset Value shall thereafter be adjusted by the Depreciation taken into account with respect to such asset for purposes of computing Profits and Losses.

          “ Hines ”: As defined in the Recitals to this Agreement.

          “ Hines Controlled Entity ”: Any partnership, limited liability company, corporation, trust or other entity which is, directly or indirectly, Controlled by (a) Hines, (b) HREH, and/or (b) Jeffrey C. Hines and/or Gerald D. Hines or, in the event of the death or disability of Jeffrey C. Hines and/or Gerald D. Hines, the heirs, legal representatives or estates of either or both of them.

          “ Hines Investment Allocation Committee ”: As defined on Schedule 4.4.

          “ Hines Limited Partner ”: As defined in the Recitals to this Agreement.

          “ HREH ”: Hines Real Estate Holdings Limited Partnership, a Texas limited partnership.

          “ Indebtedness ”: With respect to any Person, (i) any indebtedness for borrowed money evidenced by a note payable by such Person, (ii) any obligation to pay money secured by any mortgage, pledge, security interest, encumbrance, lien or charge of any kind existing on any asset owned or held by such Person, whether or not such Person has assumed or become personally liable for the obligations secured thereby, and (iii) any guaranty by such Person of the Indebtedness (as defined in clause (i) and (ii) of this definition) of another Person; provided that “Indebtedness” with respect to any Person shall not include obligations in respect of any accounts payable that are incurred in the ordinary course of such Person’s business (or guarantees by such Person of such obligations of another Person) and are not delinquent or are being contested in good faith by appropriate proceedings.

          “ Indemnified Person ”: As defined in Section 6.1.

          “ Initial Date ”: As defined in the Declaration of Trust.

          “ Initial Investment Period ”: As defined in the Fund Partnership Agreement.

          “ Initial Offering Period ”: As defined in the Fund Partnership Agreement.

          “ Initial Offering Price ”: $1000.00 per OP Unit

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          “ Investment Advisor ”: An Affiliate of Hines or SLR that provides advisory services to the General Partner pursuant to the Advisory Agreement.

          “ Investment Company Act ”: The Investment Company Act of 1940, as amended as of the date hereof and as the same may be amended from time to time, and any successor statute.

          “ Investment Guidelines ”: As defined in Section 5. l(b).

          “ Investments ”: As defined in Section 5.1(a).

          “ Investor ”: As defined in Section 3.2(a).

          “ Limited Partner ”: Any Person now or hereafter admitted as a limited partner in accordance with the terms of this Agreement. The Limited Partners as of the date hereof are the Persons identified as such on Schedule 2.1.

          “ Liquidating Event ”: As defined in Section 12.1.

          “ Liquidating Redemption ”: As defined in Section 3.10, and, as the context requires, as defined in the corresponding provisions of the Declaration of Trust and the Fund Partnership Agreement.

          “ Major Investor ”: An Investor with a Capital Commitment of at least $50 million.

          “ Majority LP Vote ”: As defined in Section 11.6(f).

          “ Management Board ”: As defined in the Fund Partnership Agreement.

          “ Moody’s ”: Moody’s Investor Services, Inc.

          “ Non-Managing General Partner ”: As defined in the Fund Partnership Agreement.

          “ NOP ”: National Office Partners Limited Partnership, a limited partnership formed by the State of California Public Employees’ Retirement System and an Affiliate of Hines.

          “ Notice of Redemption ”: As defined in Section 3.8(a), and, as the context requires, as defined in the corresponding provisions of the Declaration of Trust and the Fund Partnership Agreement.

          “ NY Trust ”: As defined in the Fund Partnership Agreement.

          “ NY Trust II ”: As defined in the Fund Partnership Agreement.

          “ Officer ”: As defined in Section 5.3.

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          “ Operating Cash Flow ”: As defined in Section 9.1.

          “ Operating Entity ”: As defined in Section 5.1(a).

          “ OP Unit ”: A unit of Partnership Interest having the rights, privileges and restrictions prescribed therefor by the terms of this Agreement.

          “ Original Agreement ”: As defined in the Recitals of this Agreement.

          “ Original GP ”: As defined in the Recitals of this Agreement..

          “ Outstanding Unit Equivalents ”: As of the end of a Fiscal Quarter or other relevant time, a number equal to the number of OP Units outstanding as of the end of such quarter or other relevant time, divided by the difference between 100% and the total Percentage Interests attributable to the Participation Interests as of the end of such Fiscal Quarter or other relevant time.

          “ Owner ”: As defined in the Property Services Agreement.

          “ Participation Interest ”: As defined in Section 3.7(c).

          “ Partner Nonrecourse Debt ”: As defined in Regulations Section 1.704-2(b)(4).

          “ Partner Nonrecourse Debt Minimum Gain ”: As defined in Regulations Section 1.704-2(i).

          “ Partner Nonrecourse Deductions ”: As defined in Regulations Section 1.704-2(i).

          “ Partners ”: Collectively, the General Partner and the Limited Partners, or any additional or successor partners of the Partnership admitted to the Partnership in accordance with the terms of this Agreement. References to a Partner shall be to any one of the Partners.

          “ Partnership ”: As defined in the Preamble to this Agreement.

          “ Partnership Auditor ”: As defined in Section 11.2.

          “ Partnership Expenses ”: As defined in Section 7.4(a).

          “ Partnership Interest ”: The ownership interest of a Partner in the Partnership at any particular time, including the right of such Partner to any and all benefits to which such Partner may be entitled as provided in this Agreement, and to the extent not inconsistent with this Agreement, under the Act, together with the obligations of such Partner to comply with all of the terms and provisions of this Agreement and the Act.

          “ Partnership Minimum Gain ”: As defined in Regulations Sections 1.704-2(b)(2) and l.704-2(d).

          “ Payment Date ”: As defined in Section 3.2(b).

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          “ Percentage Interest ”: With respect to each Partner (i) for each Fiscal Quarter ending prior to the termination of the Initial Investment Period, a percentage equal to the number of OP Units then owned by such Partner, divided by the number of OP Units then outstanding, and (ii) for each Fiscal Quarter ending after termination of the Initial Investment Period, a percentage determined for each Partner as of each Quarterly Payment Date in the following manner:

     (a)  End of Quarter Calculation of Percentage Interest Attributable to Participation Interests. As of each Quarterly Payment Date, each of Hines and SLR shall have a Percentage Interest in respect of its Participation Interest equal to the sum of:

     (i) (A) the Percentage Interest attributable to such Participation Interest as of the end of the immediately preceding Fiscal Quarter (which shall be 0% in the case of each Fiscal Quarter beginning prior to the termination of the Initial Investment Period), adjusted as provided in clause (c) below for OP Units issued during the Fiscal Quarter just ended; plus

     (ii) its AM Sharing Percentage (as defined below) of a fraction (A) whose numerator is 0.09375% of the aggregate Unrecovered Capital of all Class A Major Investors, plus 0.10625% of the aggregate Unrecovered Capital of all Class B Major Investors, plus 0.1125% of the aggregate Unrecovered Capital of all Class C Major Investors, plus 0.11875% of the aggregate Unrecovered Capital of all Class D Major Investors, plus 0.125% of the aggregate Unrecovered Capital of all Unaffiliated Limited Partners that are not Major Investors, each determined as of the end of the current Fiscal Quarter, and (B) whose denominator is the Current Total Equity Value of the Partnership as of the end of the current quarter; plus

     (iii) (A) its AQ Sharing Percentage (as defined below) of 0.5% of the Gross Real Estate Investments (as defined below) made by the Partnership during the Fiscal Quarter just ended, multiplied by (B) the aggregate Percentage Interest of the Unaffiliated Limited Partners in respect of their OP Units only immediately prior to any adjustment under clause (d) below, divided by (C) the Current Total Equity Value of the Partnership as of the end of the Fiscal Quarter just ended.

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     (b)  When Change to Participation Interest Becomes Effective. The Percentage Interest determined under clause (a) as of the end of a particular Fiscal Quarter shall become effective as of the beginning of the immediately following Fiscal Quarter.

     (c)  Adjustment of Percentage Interests Attributable to Participation Interest Following Issuance or Redemption of OP Units. Immediately after the issuance or redemption by the Partnership of any OP Units, the Percentage Interest attributable to the Participation Interest shall be adjusted so that it equals (i) the Percentage Interest attributable to the Participation Interest immediately prior to the issuance or redemption of such OP Units, multiplied by (ii) a fraction whose numerator is (A) the number of Outstanding Unit Equivalents immediately prior to the issuance or redemption of such OP Units and whose denominator equals (B) the number of Outstanding Unit Equivalents immediately prior to the issuance or redemption of such Partnership, plus the number of OP Units then being issued, or minus the number of OP Units then being redeemed, as the case may be.

     (d)  Calculation of Percentage Interests of Partners’ Holding OP Units. As of each Quarterly Payment Date, each Partner holding OP Units shall have a Percentage Interest in respect of such OP Units equal to (i) 100%, minus the sum of the Percentage Interests attributable to the Participation Interests determined pursuant to clauses (a) and (c) above, multiplied by (ii) a fraction whose numerator is the number of OP Units then owned by such Partner and whose denominator is the total number of OP Units outstanding.

     (e)  Calculation of Total Percentage Interests of Hines and SLR. The total Percentage Interest of Hines and SLR, as the case may be, shall equal such person’s Percentage Interest in respect of its Participation Interest (determined under clauses (a) and (c) above), plus such person’s Percentage Interest in respect of its OP Units (determined under clause (d) above).

          “ Person ”: An individual, corporation, partnership, limited liability company, estate, trust, association, joint stock company or other legal entity, or a group as that term is used for purposes of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended.

          “ Prime Rate ”: The rate of interest per annum announced from time to time by JPMorgan Chase Bank, or its successor, at its principal office in New York City as its prime rate.

          “ Priority Redemption Right ”: As defined in Section 3.9.

          “ Priority Redemptions ”: As defined in Section 3.9, and, as the context requires, as defined in the Fund Partnership Agreement and the Declaration of Trust.

          “ Private Placement FTP Exemption ”: The exemption from publicly traded partnership status provided in Regulation Section 1.7704-l(h) (which generally applies if (i) all interests in a partnership are issued in a transaction or series of transactions that are not required to be registered under the Securities Act and (ii) the partnership does not have more than 100 partners at any time during taxable year of the partnership).

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          “ Private Transfer ”: Any of the following:

     (i) transfers in which the basis of the Partnership Interest in the hands of the transferee is determined, in whole or in part, by reference to its basis in the hands of the transferor or is determined under Code Section 732;

     (ii) transfers at death, including transfers from an estate or testamentary trust;

     (iii) transfers between members of a family;

     (iv) transfers involving the issuance of interests by (or on behalf of) the Partnership in exchange for cash, property, or services;

     (v) transfers involving distributions from a qualified retirement plan or an individual retirement account;

     (vi) the transfer by a Partner and any related persons (within the meaning of Code Section 267(b) or 707(b)(l)) in one or more transactions during any thirty calendar day period of Partnership Interests representing in the aggregate more than 2 percent of the total interests in Partnership capital or profits;

     (vii) transfers by one or more Partners of interests representing in the aggregate 50 percent or more of the total interests in Partnership capital and profits in one transaction or a series of related transactions; and

     (viii) transfers not recognized by the Partnership within the meaning of Regulation Section 1.7704-l(d)(2) (i.e., the Partnership neither admits the transferee as a partner nor recognizes any rights of the transferee as a partner).

          “ Profits ” and “ Losses ”: For each Fiscal Year or portion thereof, an amount equal to the Partnership’s items of taxable income or loss for such year or period, determined by the General Partner in accordance with Code Section 703(a) with the following adjustments:

     (i) any income which is exempt from federal income tax and not otherwise taken into account in computing Profits or Losses shall be added to taxable income or loss;

     (ii) any expenditures of the Partnership described in Code Section 705(a)(2)(B) or treated as Code Section 705(a)(2)(B) expenditures under Regulations Section 1.704-l(b)(2)(iv)(i) and not otherwise taken into account in computing Profits or Losses, will be subtracted from taxable income or loss;

     (iii) in the event that the Gross Asset Value of any Partnership asset is adjusted pursuant to the definition of Gross Asset Value contained in this Article I, the amount of such adjustment shall be taken into account as gain or loss from the disposition of such asset for purposes of computing Profits and Losses;

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     (iv) gain or loss resulting from any disposition of Partnership assets 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;

     (v) 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 or other period;

     (vi) 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 complete liquidation of a Partner’s Partnership Interest, or is required pursuant to the last sentence of Regulations Section 1.704-l(b)(2)(iv)(m)(2) to be taken into account in determining Capital Accounts, 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 Profits or Losses; and

     (vii) any items specially allocated pursuant to Section 8.6 or Section 8.7 shall not be considered in determining Profits or Losses.

          “ Property ”: As defined in Section 5.1(a).

          “ Property Manager ”: As defined in Section 5.6.

          “ Property Services Agreement ”: As defined in Section 5.6.

          “ Property Services Agreement Form ”: As defined in the Fund Partnership Agreement.

          “ Quarterly Payment Date ”: The first Business Day following the end of each Fiscal Quarter.

          “ Recapitalization ”: As defined in Section 3.8(d).

          “ Redeeming Partner ”: As defined in Section 3.8(a).

          “ Redemption Amount ”: Either the Cash Amount or the REIT Shares Amount as determined pursuant to Section 3.8.

          “ Redemption Right ”: As defined in Section 3.8(a).

          “ Regulations ”: The Income Tax Regulations, including Temporary Regulations, promulgated under the Code, as such regulations may be amended from time to time (including corresponding provisions of succeeding regulations).

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          “ Regulatory Allocations ”: As defined in Section 8.7.

          “ REIT ”: As defined in Section 5.7.

          “ REIT Distribution Objectives ”: As defined in Section 9.6.

          “ REIT Requirements ”: As defined in Section 5.7.

          “ REIT Shares Amount ”: A number of Shares equal to (i) the number of OP Units offered for redemption by a Redeeming Partner, plus (ii) (A) the Current Participation Interest Value associated with the portion of the Participation Interest offered for redemption by a Redeeming Partner, multiplied by (B) a fraction whose numerator equals the number of OP Units outstanding and whose denominator equals the difference between the Current Total Equity Value and the Current Participation Interest Value.

          “ Required Vote ”: As defined in Section 13.3(a).

          “ Rights ”: As defined in Section 3.8(e).

          “ S&P ”: Standard & Poor’s, a division of The McGraw-Hill Companies, Inc.

          “ Securities Act ”: The Securities Act of 1933, as amended.

          “ Selected Prior Closing Partner ”: As defined in Section 3.3(b).

          “ Shareholder ”: As defined in the Declaration of Trust.

          “ Shares ”: As defined in Section 6.1 of the Declaration of Trust.

          “ Similar Law ”: Any federal, state, local, non-U.S. or other law or regulation that contains one or more provisions that are similar to any of the provisions contained in Title I of ERISA or Section 4975 of the Code.

          “ Single Asset Debt Limit ”: As defined in Section 3.6(a)(i)(B).

          “ SLR ”: As defined in the Recitals to this Agreement.

          “ SLR Designee ”: As defined in the Fund Partnership Agreement.

          “ Specified Redemption Date ”: As defined in Section 3.8(a).

          “ Subscription Agreement ”: As defined in Section 3.2(a).

          “ Subsequent Closing ”: As defined in Section 3.3(b).

          “ Subsequent Closing Partner ”: As defined in Section 3.3(b).

          “ Super Majority LP Vote ”: As defined in Section 11.6(f).

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          “ Tax Matters Partner ”: As defined in Section 11.4(a).

          “ Temporary Investment ”: Any repurchase agreements of primary Federal Reserve dealers using treasury securities only; bankers acceptances which are legal for purchase by the Federal Reserve Bank; United States Treasury bills and agency discount notes; commercial paper that is rated by Moody’s or S&P in its highest rating category; accounts or mutual funds which invest in any of the foregoing; and any other investment approved by the Advisory Committee as a Temporary Investment.

          “ Term ”: As defined in Section 2.9.

          “ Transfer ”: As a noun, any sale, transfer, gift, exchange, assignment, devise or other disposition, as well as any other event that causes any Person to acquire beneficial ownership, or any agreement to take any such actions or cause any such events, with respect to Partnership Interests, or the right to vote or receive distributions with respect to Partnership Interests, including (a) the granting or exercise of any option (or any disposition of any option), (b) any disposition of any securities or rights convertible into or exchangeable for Partnership Interests or any interest in Partnership Interests or any exercise of any such conversion or exchange right and (c) Transfers of interests in other entities that result in changes in beneficial ownership of Partnership Interests; in each case, whether voluntary or involuntary, whether owned of record or beneficially owned, and whether by operation of law or otherwise. The terms “Transferor,” “Transferee,” “Transferred” and “Transferring” have correlative meanings.

          “ Trust ”: As defined in the Preamble to this Agreement.

          “ Unaffiliated Limited Partner ” A Limited Partner that is not an Affiliate of the General Partner or of Hines.

          “ Unfunded Commitment ”: As defined in Section 3.2(a).

          “ Unrecovered Capital ”: An amount, determined for each Limited Partner, which equals the aggregate amount of all Capital Contributions made by such Limited Partner to the Partnership less the aggregate amount of capital returned to such Limited Partner by the Partnership by either the redemption of OP Units or the distribution of Capital Cash Flow.

          “ Voting Fund Investors ”: As defined in the Fund Partnership Agreement.

          “ Withdrawn General Partner ”: As defined in Section 12.1.

          “ 75% Majority LP Vote ”: As defined in Section 11.6(f).

          SECTION 1.2 Interpretation; Terms Generally. The definitions set forth in Section 1.1 and elsewhere in this Agreement shall apply equally to both the singular and plural forms of the terms defined. Whenever the context may require, any pronoun shall include the corresponding masculine, feminine and neuter forms. Unless otherwise indicated, the words “include”, “includes” and “including” shall be deemed to be followed by the phrase “without limitation.” The words “herein”, “hereof and “hereunder” and words of similar import shall be deemed to refer to this Agreement (including the Exhibits and Schedules) in its entirety and not

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to any part hereof, unless the context shall otherwise require. All references herein to Articles, Sections, Exhibits and Schedules shall be deemed to refer to Articles and Sections of, and Exhibits and Schedules to, this Agreement, unless the context shall otherwise require. Unless the context shall otherwise require, any references to any agreement or other instrument or statute or regulation are to it as amended and supplemented from time to time (and, in the case of a statute or regulation, to any corresponding provisions of successor statutes or regulations). Any reference in this Agreement to a “day” or number of “days” (that does not refer explicitly to a “Business Day” or “Business Days”) shall be interpreted as a reference to a calendar day or number of calendar days. If any action or notice is to be taken or given on or by a particular calendar day, and such calendar day is not a Business Day, then such action or notice shall be deferred until, or may be taken or given on, the next Business Day.

ARTICLE II

General Provisions

          SECTION 2.1 Formation and Continuation. The Partnership was formed as a limited partnership under the Act by the filing of its certificate of limited partnership (the “ Certificate ”) with the Secretary of State of the State of Delaware on March 5, 2003. The Original GP shall have no right, title or interest in or to the Partnership and no rights or obligations under this Agreement other than its rights as an Indemnified Person under Sections 6.1 and 6.2. The General Partner shall continue as the general partner of the Partnership and each Person admitted as a Limited Partner shall continue as a limited partner of the Partnership. As of the date hereof, each Person identified as a Limited Partner on Schedule 2.1 is a Limited Partner. The General Partner may amend Schedule 2.1 from time to time to reflect the admission of additional Limited Partners.

          SECTION 2.2 Name. The name of the Partnership shall be “Hines-Sumisei US Core Office Properties LP.” The General Partner shall, with the affirmative written consent of SLR (which consent shall not be unreasonably withheld) and upon notice to the Limited Partners, have the right to change the name of the Partnership and, in connection therewith, may execute and file (pursuant to the power-of-attorney provided for in Section 13.2, where necessary) such amendments to this Agreement, the Certificate and such other documentation, as shall be necessary or desirable to effect such name change. The Partnership shall do business under the name of the Partnership or under such other name (including any assumed name) as the General Partner may from time to time determine in its sole discretion. Upon the dissolution and termination of the Partnership, the General Partner shall retain all rights with respect to the name of the Partnership and the use of such name.

          SECTION 2.3 Organizational Certificates and Other Filings. If requested by the General Partner, the Limited Partners will promptly execute all certificates and other documents consistent with the terms of this Agreement necessary for the General Partner to accomplish all filing, recording, publishing and other acts as may be appropriate to comply with all requirements for (a) the formation and operation of a limited partnership under the laws of the State of Delaware, (b) if the General Partner deems it advisable, the operation of the Partnership as a limited partnership, or partnership in which the Limited Partners have limited liability, in all

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jurisdictions where the Partnership proposes to operate and (c) all other filings required to be made by the Partnership.

          SECTION 2.4 Principal and Other Offices. The principal executive office of the Partnership shall be c/o Hines Interests Limited Partnership, 2800 Post Oak Boulevard, Suite 5000, Houston, Texas 77056-6118, or such other place as may from time to time be designated by the General Partner in its sole discretion. The General Partner shall give prompt notice to each Partner of any change in the principal office of the Partnership. The Partnership may also have such other offices and places of business as the General Partner determines to be appropriate.

          SECTION 2.5 Registered Office; Registered Agent. The address of the registered office of the Partnership in the State of Delaware shall be c/o Corporation Trust Company, 1209 Orange Street, Wilmington, Delaware 19801 or such other place as may be designated from time to time by the General Partner in its sole discretion. The name and address of the registered agent for the Partnership in the State of Delaware which shall act as its agent for service of process in the State of Delaware shall be The Corporation Trust Company, 1209 Orange Street, Wilmington, Delaware 19801, or such other agent as may be designated from time to time by the General Partner in its sole discretion.

          SECTION 2.6 Purpose. The purpose of the Partnership is to make, hold, own, sell, convey, exchange, transfer or otherwise dispose of investments in accordance with the Investment Guidelines and to engage in such other activities as are permitted hereby or are incidental or ancillary thereto as the General Partner deems necessary or advisable, all upon the terms and conditions set forth in this Agreement.

          SECTION 2.7 Powers. The Partnership shall have all the powers now or hereafter conferred by the laws of the State of Delaware on limited partnerships formed under the Act and, subject to the express limitations set forth in this Agreement, may do any and all lawful acts or things that are necessary, appropriate, incidental or convenient for the furtherance and accomplishment of the purposes of the Partnership or for the protection and benefit of the Partnership or its properties and assets. Without limiting the generality of the foregoing, and subject to the terms of this Agreement, the Partnership may enter into, deliver and perform all contracts, agreements and other undertakings and engage in all activities and transactions as may be necessary or appropriate to carry out its purposes and conduct its business. Without limiting the generality of the foregoing, the Partnership, and the General Partner on behalf of the Partnership, are authorized and empowered to enter into, deliver and perform the Partnership’s obligations under the Advisory Agreement.

          SECTION 2.8 Fiscal Year. The fiscal year (“ Fiscal Year ”) and taxable year of the Partnership will be the calendar year, and its fiscal quarters (each, a “ Fiscal Quarter ”) shall end on the last day of each calendar quarter. The General Partner may change the ending date of the Fiscal Year if the General Partner determines in good faith that such change is necessary or appropriate. The General Partner will change the taxable year of the Partnership if and to the extent necessary to comply with Code Section 706 and the Regulations thereunder. The General Partner will give prompt written notice of any such change to the Limited Partners.

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          SECTION 2.9 Term. The term of the Partnership (the “ Term ”) commenced upon the filing of the Certificate and shall continue until the Partnership is dissolved and its affairs are wound up in accordance with Article XII.

          SECTION 2.10 Feeder Entities. In order to facilitate investment in the Partnership by certain investors, the General Partner may establish or facilitate the establishment of one or more collective investment vehicles or other arrangements (each such vehicle or arrangement, a “ Feeder Entity ”) through which investors may invest in the Partnership by acquiring interests in such Feeder Entity. Affiliates of the General Partner may hold interests in any such Feeder Entity or in the general partner (or advisor or similar entity) of such Feeder Entity. In case of a default by any such Feeder Entity, the General Partner may treat one or more of such investors (rather than such Feeder Entity) as a Defaulting Limited Partner as provided in Section 10.6. In addition, the terms of the governance and/or organizational documents of any such Feeder Entity may permit the payment to the general partner (or advisor or similar entity) of such Feeder Entity of management, advisory or other fees, and any such fees paid by such Feeder Entity to its general partner (or advisor or other entity) may be used to reduce and offset the Asset Management Fee or Acquisition Fees payable under this Agreement, in which event the General Partner shall amend this Agreement so that the benefit of any such reduction inures to such Feeder Entity.

ARTICLE III

Partnership Capital

          SECTION 3.1 Partnership Capital. As of the date of this Agreement, the Partners have been issued OP Units and have Funded Commitments in the amounts set forth opposite their names on Schedule 3.1 . The General Partner shall record all issuances and redemptions of OP Units on the books of the Partnership.

          SECTION 3.2 Capital Commitments.

     (a) The Partnership may from time to time, at the discretion of the General Partner, issue additional OP Units and admit additional Limited Partners to the Partnership. Any Person (other than the Trust) that acquires a Partnership Interest for cash (an “ Investor ”) after the date hereof will acquire such interest pursuant to an agreement (a “ Subscription Agreement ”) between such Investor and the Partnership pursuant to which such Investor agrees to acquire, and the Partnership agrees to issue, a specified number of OP Units in exchange for Capital Contributions in cash at a specified price per OP Unit, all on such terms and conditions as are provided in this Agreement and as may be provided in such Subscription Agreement. A Subscription Agreement shall become effective as of the date it has been executed and delivered by the Investor party thereto and accepted by the General Partner on behalf of the Partnership. OP Units issuable pursuant to a Subscription Agreement may be issuable in installments, with each installment being issuable, and the Capital Contribution therefore being payable, in accordance with calls for capital (“ Capital Calls ”) issued pursuant to written notice (the “ Capital Call Notice ”) to the Investor party to such Subscription Agreement. The total purchase price payable by any Investor under a Subscription Agreement for the OP Units

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issuable pursuant thereto is referred to as such Investor’s “Capital Commitment”. Each Investor which acquires any OP Units pursuant to a Subscription Agreement shall be deemed to be admitted to the Partnership as a Limited Partner immediately upon the payment of the purchase price for the first OP Units so issued to such Investor. The aggregate amount of Capital Contributions made by a Partner (in cash or property) is referred to herein as such Partner’s “ Funded Commitment ,” and the portion of the Capital Commitment provided for in any Subscription Agreement that remains unpaid after any closing of a purchase and issuance of OP Units pursuant thereto shall be referred to as the “Unfunded Commitment” of the Limited Partner party to such Subscription Agreement. Subject to Section 11.4(c), in no event will any Limited Partner be required to contribute any capital to the Partnership in excess of such Limited Partner’s Capital Commitment.

     (b) If at any time the General Partner determines to raise capital by issuing Capital Calls to Partners having Unfunded Commitments, it shall generally coordinate the issuance of such Capital Calls with the Fund General Partner so that capital is called pro rata from all Fund Investors having unfunded commitments to contribute capital to the Fund Partnership, the Trust and/or the Partnership based on the relative unfunded commitments of such Fund Investors to such Entities. However, the General Partner and Fund General Partner may, in their discretion, issue Capital Calls other than on such a pro rata basis to the extent required by the terms of any Subscription Agreement or other agreement between the Partnership or the General Partner and one or more Partners, or if the General Partner or the Fund General Partner otherwise deems it advisable to issue Capital Calls in some manner other than on such a pro rata basis (for example, to assist in achieving or maintaining the status of the Trust as a “domestically controlled” REIT). Each Capital Call Notice issued by the General Partner shall specify the account to which Capital Contributions are to be delivered pursuant thereto and the date on which such Capital Contributions are due (“ Payment Date ”) which date shall be no sooner than ten Business Days after the date such Capital Call Notice is issued. All Capital Contributions made on or before the Payment Date specified in a Capital Call Notice shall be deemed to have been made on such Payment Date.

          SECTION 3.3 Initial Offering Period.

     (a) All Subscription Agreements entered into during the Initial Offering Period shall provide for the issuance of OP Units at the Initial Offering Price; provided that any such Subscription Agreement may, in the discretion of the General Partner, provide for the issuance of OP Units at a price different from the Initial Offering Price in any Subscription Agreement entered into after the date of this Agreement if, in the reasonable determination of the General Partner in its sole discretion, such different price is appropriate based on any appreciation or depreciation of any Investments from the date of this Agreement to the effective date of such Subscription Agreement; provided further. that no Subscription Agreement entered into during the Initial Offering Period shall provide for the issuance of OP Units at a price per OP Unit less than the Initial Offering Price without the consent of the Limited Partners holding OP Units immediately prior to the effective date of such Subscription Agreement by a Majority LP Vote.

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     (b) If, following a closing of the issuance of OP Units during the Initial Offering Period (any such closing, a “ Subsequent Closing ”), there remain any Unfunded Commitments, then each Limited Partner that was admitted or increased its Capital Commitment at such Subsequent Closing may (a “Subsequent Closing Partner”) may, at the discretion of the General Partner, be required to make a Capital Contribution (and be issued OP Units in respect thereof) in an amount up to its pro rata share (based on the Capital Commitments of all Partners immediately after such Subsequent Closing) of the Funded Commitments of all Partners holding OP Units immediately prior to such Subsequent Closing. The General Partner may, in its discretion, use the proceeds of any such Capital Contributions to redeem OP Units held by one or more Partners (selected at the discretion of the General Partner) holding OP Units immediately prior to such Subsequent Closing (each, a “Selected Prior Closing Partner”) at the same price per OP Unit at which such OP Units were acquired by such Selected Prior Closing Partner, such that, after making such Capital Contributions and redemptions, each Subsequent Closing Partner’s Funded Commitment relative to its Capital Commitment is the same as or less than the Funded Commitment of each Selected Prior Closing Partner relative to its Capital Commitment. The Funded Commitment of any Partner having OP Units redeemed pursuant to the preceding sentence shall be reduced by the amount received by such Partner for the OP Units redeemed, such Partner’s Unfunded Commitment shall be increased by such amount, and such Partner shall remain obligated to purchase additional OP Units at the price per share provided for in its Subscription Agreement to the full extent of its Unfunded Commitment as so increased.

          SECTION 3.4 Initial Investment Period. Upon the termination of the Initial Investment Period, any remaining Unfunded Commitments attributable to Subscription Agreements entered into during the Initial Offering Period shall be canceled automatically and without any further action by any party, and the General Partner shall have no further right to issue Capital Calls, and Investors shall have no further right to purchase OP Units in respect of such canceled Unfunded Commitments pursuant to any such Subscription Agreement; provided that the foregoing shall not affect (i) the right of the General Partner or the Partnership to pursue any remedies available to it under this Agreement or at law in respect of any default in respect of a Capital Call issued prior to the termination of the Initial Investment Period, or (ii) the obligation of any Limited Partner with respect to a Capital Commitment attributable to a Subscription Agreement entered into after the Initial Offering Period.

          SECTION 3.5 Additional Capital.

     (a) Except as specifically provided in this Agreement or any Subscription Agreement, no Partner (including the General Partner) shall be required to, and no Limited Partner shall have the right to, contribute additional funds or other property to the Partnership. The Partnership may from time to time incur Indebtedness in accordance with Section 3.6 and issue additional OP Units in accordance with Section 3.7.

     (b) Except (i) for the net proceeds of the issuance by the Trust of debt securities that are loaned by the Trust to the Partnership, and (ii) where the Trust determines that the net proceeds generated by the issuance of additional Shares or other securities (whether for debt or equity) shall be retained by the Trust for a valid business

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reason consistent with the purposes of the Partnership and such retention does not materially adversely affect the Limited Partners, the net proceeds of any and all funds raised by or through the Trust through the issuance of Shares or other securities shall be contributed to the Partnership as additional Capital Contributions, in which event the Trust shall be issued additional OP Units in accordance with Section 3.7.

          SECTION 3.6 Partnership Indebtedness.

     (a) The General Partner shall have the right, at its option, to cause the Partnership to incur or assume Indebtedness from any Person for any Partnership purpose including to cover Partnership Expenses, make Investments, provide permanent financing or provide interim financing to the extent necessary to consummate the purchase of Investments prior to completion of the permanent debt financing therefor or prior to the receipt of Capital Contributions, and to pledge or otherwise encumber assets of the Partnership or any Operating Entity to secure any such Indebtedness, subject to the following:

     (i) The Partnership shall not incur any Indebtedness unless after giving effect to such incurrence,

     (A) the aggregate amount of Indebtedness of the Partnership, the Trust and the Fund Partnership is not more than 50% of the Current Market Value of all of the Partnership’s Investments at the time any such Indebtedness is incurred (the “ Aggregate Debt Limit ”); and

     (B) the total amount of Indebtedness that is secured by any one Investment shall not exceed 65% of the Current Market Value of such Investment at the time such Indebtedness is incurred (the “Single Asset Debt Limit ”).

     (ii) Notwithstanding clause (i) of this Section 3.6(a), the General Partner may cause the Partnership to incur Indebtedness in excess of the Aggregate Debt Limit and/or the Single Asset Debt Limit if the General Partner determines that it is advisable to do so in connection with the acquisition of a new Investment; provided that, at the time such excess Indebtedness is incurred, the General Partner makes a reasonable determination that the aggregate Indebtedness of the Partnership, the Trust and the Fund Partnership will be within the Aggregate Debt Limit, and the Indebtedness secured by such Investment will be within the Single Asset Debt Limit, within one year after the incurrence of such excess Indebtedness.

     (b) The General Partner may cause the Partnership to issue debt securities to the Trust in exchange for funds that the Trust has raised through the incurrence of Indebtedness or the issuance of debt securities; provided that (i) the terms of the debt securities so issued by the Partnership are substantially the same as the terms of the Indebtedness incurred or the debt securities issued by the Trust in respect of such funds, and (ii) the principal amount of the debt securities so issued by the Partnership, taken

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together with other Indebtedness of the Partnership, the Trust and the Fund Partnership, but without duplication of the corresponding debt securities issued by the Trust, would not exceed the Aggregate Debt Limit.

     (c) In connection with the incurrence of Indebtedness, the General Partner shall have the right, in its discretion, to pledge to the lender the right of the General Partner to issue Capital Calls in respect of the Unfunded Commitments of the Partners, and to enforce the obligations of the Limited Partners to make Capital Contributions in respect thereof, in accordance with the terms and conditions of this Agreement and the Subscription Agreements. Each Limited Partner having an Unfunded Commitment shall, upon the written request of the General Partner, for the benefit of one or more lenders or other Persons extending credit to the Partnership, (A) acknowledge its obligations pursuant to this Agreement and its Subscription Agreement to make Capital Contributions (which may, as determined by the General Partner, include an acknowledgment that the General Partner or the lender on behalf of the General Partner (in accordance with the agreements between such lender and the Partnership and/or the General Partner), may call such Capital Contributions in accordance with this Agreement and such Limited Partner’s Subscription Agreement to pay the outstanding obligations to such lenders without, except as expressly set forth in this Agreement, defense, counterclaim or offset of any kind); provided that the liability of the Limited Partners to make Capital Contributions shall not be increased thereby and shall not result in the loss of a Limited Partner’s limited liability status under this Agreement, and (B) execute such documents as may be reasonably required to create a security interest in such Limited Partner’s obligations to make such Capital Contributions, which the General Partner may perfect and assign for the benefit of a lender as determined by the General Partner in its sole discretion. For purposes of determining whether the aggregate Indebtedness of the Partnership, the Trust and the Fund Partnership is within the Aggregate Debt Limit, Indebtedness secured by a pledge of the General Partner’s right to make Capital Calls in respect of the Partners’ Unfunded Commitments shall not be treated as outstanding Indebtedness; provided that no assets of the Partnership are pledged to secure such Indebtedness other than the right of the General Partner to issue Capital Calls in respect of the Unfunded Commitments of the Partners and to enforce the obligations of the Limited Partners to make Capital Contributions in respect thereof.

          SECTION 3.7 Issuance of OP Units and Participation Interests. The General Partner shall cause the Partnership to issue additional OP Units and Participation Interests from time to time as follows:

     (a) The Partnership shall issue OP Units to the Trust upon the issuance by the Trust of additional Shares (other than in exchange for OP Units) and the contribution of the net proceeds thereof as a Capital Contribution to the Partnership as provided for in Section 3.7(b), it being understood, however, that (i)(A) the Trust may issue Shares upon conversion or exchange of any securities issued by the Trust in accordance with the terms of the Declaration of Trust and that are convertible into or exchangeable for Shares in cases where the Trust then owns comparable securities in the Partnership that are convertible or exchangeable for OP Units or (B) the Trust may issue Shares in lieu of fees or compensation for services to the Trust, the Partnership or any Operating Entity without

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receiving any proceeds, and (ii) the issuance of Shares as described in clauses (i)(A) and (i)(B) shall nonetheless entitle the Trust to receive additional OP Units pursuant to this Section 3.7(a) (provided that, in the case of transactions described in clause (i)(A), the Trust actually exchanges or converts such Partnership securities). The number of OP Units issued to the Trust pursuant to this Section 3.7(a) shall be equal to the number of Shares issued by the Trust.

     (b) The Partnership may issue OP Units, as determined by the General Partner in its discretion, to existing or newly-admitted Partners, (i) in exchange for the making by such a Partner (a “ Contributing Partner ”) of a Capital Contribution to the Partnership in cash, or (ii) in connection with the acquisition, directly or indirectly, of an Investment from such Contributing Partner or an Affiliate of such Contributing Partner by the Partnership or a Fund Entity in which the Partnership, has a direct or indirect interest; provided, that no OP Units may be issued pursuant to this Section 3.7(b) at a price per OP Unit that is less than the Current Unit Value as of the date on which the Partnership enters into a binding agreement to issue such OP Units without the consent of the Limited Partners by a Majority LP Vote. The General Partner will not permit the Partnership or any Fund Entity that the Partnership Controls to issue equity interests to third party investors at a valuation that reflects a valuation of any Property in which the Partnership or such Fund Entity has a direct or indirect interest of less than Current Market Value as of the date a binding commitment is made for the issuance of such equity interests without the written consent of Voting Fund Investors holding, without duplication, sixty- six and two-thirds percent (66 2/3%) or more of the aggregate outstanding equity interests in the Fund Partnership, the Trust and the Partnership held by Voting Fund Investors, excluding any equity interest which is specifically designated a non-voting interest under the Constituent Documents of the issuer of such equity interest.

     (c) Effective as of the date hereof, the Partnership is issuing to each of Hines and SLR a limited partnership interest denominated as a “ Participation Interest. ” The Participation Interest is an equity interest in the Partnership which is granted in consideration for services rendered by Hines and SLR as Investment Advisors to the Fund pursuant to the Advisory Agreement. The Participation Interest is in addition to, and distinct from, the OP Units described above, and any references to “OP Units” shall not be deemed to include the Participation Interest. A Partner’s percentage interest attributable to its Participation Interest (if any), together with the percentage of the total outstanding OP Units held by it, equal its Percentage Interest in the Partnership. The Participation Interest is an interest solely in profits and shall not have any Capital Commitment or initial Capital Account associated with it. It is intended that the Participation Interest constitute a profits interest within the meaning of Section 2.02 of IRS Revenue Procedure 93-27, 1993-2 C.B. 343.

     (i) The formula for the calculation of the Participation Interest is included in the definition of Percentage Interest in Section 1.1. The Participation Interest is intended to provide each Investment Advisor holding it with an interest in the Partnership that approximates the interest it would acquire if it received Asset Management Fees and Acquisition Fees after the Initial Investment Period in the same amounts payable in respect of such fees during the Initial Investment

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Period and then invested half of such amounts in the Partnership through the acquisition of additional OP Units. (However, since the Participation Interest is a profits interest, this interest will be substantially economically equivalent to the ownership of OP Units only if the Partnership has adequate gain or profit to allocate to the holder of the Participation Interest.) Without considering the effect of additional equity investments or redemptions by existing or new Partners, the grant of the Participation Interest has the effect of decreasing the Percentage Interest of all Unaffiliated Limited Partners after the Initial Investment Period as the Percentage Interest associated with the Participation Interests increases in a manner corresponding to the accrual of additional Asset Management Fees and Acquisition Fees that would occur if such fees were payable in cash after the Initial Investment Period in the same amounts as such fees are payable during the Initial Investment Period pursuant to the terms of this Agreement. This is accomplished by the OP Unit cancellation procedure described in Section 5.9. (Schedule 5.9 of the Fund Partnership Agreement provides an example of OP Unit cancellations as contemplated by Section 5.9.)

     (ii) SLR may, at any time prior to the end of the Initial Investment Period, elect to return its Participation Interest to the Partnership by giving written notice to such effect to the General Partner. In such event, the General Partner shall amend this Agreement and the Advisory Agreement (in a manner reasonably acceptable to SLR) as necessary to provide for (A) only Hines having a Percentage Interest calculated by reference to a Participation Interest, and (B) the payment to the General Partner for the benefit of SLR of additional cash amounts in respect of Asset Management Fees and Acquisition Fees to which SLR would be entitled under the Advisory Agreement if the Partnership continued to pay such fees after the Initial Investment Period in the manner that such fees are required to be paid under this Agreement during the Initial Investment Period.

     SECTION 3.8 Redemption Rights.

     (a) Subject to the provisions of Sections 3.8(b) and (d), each Limited Partner shall have the right (a “ Redemption Right ”) to require the Partnership to redeem all or a portion of the OP Units and/or Participation Interest held by such Limited Partner at a redemption price equal to and in the form of the Redemption Amount at any time after the later of (i) the last day of the Initial Investment Period and (ii) the first anniversary of the date such Limited Partner acquired the OP Units it seeks to redeem. The Redemption Right shall be exercised pursuant to a notice (a “ Notice of Redemption ”) delivered to the Partnership (with a copy to the General Partner) by the Limited Partner who is exercising the Redemption Right (the “ Redeeming Partner ”); provided , however , that the Partnership shall not be obligated to satisfy such Redemption Right if the Trust elects to purchase the OP Units and/or Participation Interest subject to the Notice of Redemption pursuant to Section 3.8(c). The Redeeming Partner shall have no right, with respect to any OP Units and/or Participation Interests so redeemed, to receive any distribution paid with respect to OP Units if the record date for such distribution is on or after the tenth Business Day following the date the General Partner receives the Notice of Redemption (the “ Specified Redemption Date ”). If, and beginning with the first day of the first

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taxable year in which, the Partnership no longer qualifies for the Private Placement FTP Exemption, the Redemption Right shall comply with the requirements of Regulations Section 1.7704-l(f) and shall be construed and administered in accordance therewith. The General Partner may modify the Redemption Right from time to time in its discretion to ensure that the terms of the Redemption Right comply and continue to comply with such requirements.

     (b) In addition to other restrictions on Redemption Rights in any other provision of this Agreement, the following restrictions apply to all Redemption Rights (other than the redemption right of the Trust set forth in Section 3.12):

     (i) Notwithstanding any other provision of this Article III, but subject to the last sentence of clause (iii) below, a Limited Partner shall be entitled to exercise the Redemption Right only if (x) the redemption or purchase of the Limited Partner’s OP Units and Participation Interest, as the case may be, would constitute a Private Transfer or (y) the Percentage Interest attributable to the OP Units and Participation Interest to be purchased or redeemed, when aggregated with other Transfers of OP Units within the same taxable year of the Partnership (but not including Private Transfers), would constitute a Percentage Interest often percent (10%) or less.

     (ii) The General Partner may establish such policies and procedures as it may deem necessary or desirable in its discretion to administer the 10% limit set forth in subparagraph (i) above, including imposing further limitations on the number of OP Units and portion of Participation Interest with respect to which the Redemption Right may be exercised during any period of time shorter than a calendar year and establishing procedures to allocate the ability to exercise the Redemption Right among the Limited Partners.

     (iii) The restrictions set forth in subparagraphs (i) and (ii) of this Section 3.8(b) shall continue in effect until such time as the Partnership is no longer potentially subject to classification as a publicly traded partnership, as defined in Code Section 7704, in the absence of such restrictions, as determined by the General Partner in its discretion. The restrictions set forth in such clauses (i) and (ii), together with the restrictions on the Transfer of Partnership Interests set forth in Section 10.3(a)(iii), are intended to limit transfers of interests in the Partnership in such a manner as to permit the Partnership to qualify for the safe harbors from treatment as a publicly traded partnership set forth in Treasury Regulations Sections 1.7704-l(d), (e), (f) and (j) and shall be construed and administered in accordance therewith. The General Partner may modify the restrictions set forth in such clauses (i) and (ii), and the provisions of Section 10.3(c), from time to time in its discretion to ensure that the Partnership complies and continues to comply with the requirements of the Code and Regulations described above. Notwithstanding anything herein to the contrary, the provisions of subparagraphs (i)-(iii) shall only apply if, and beginning with the first day of the first taxable year in which, the Partnership no longer qualifies for the Private Placement PTP Exemption.

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     (iv) A Limited Partner shall not be entitled to exercise a Redemption Right if such exercise (assuming, in the case of the exercise of a Redemption Right, that the Trust elects to purchase all OP Units and/or Participation Interests proposed to be redeemed in exchange for Shares pursuant to Section 3.8(c)) would (a) result in the total number of outstanding Shares and any other ownership or beneficial interests in the Trust being owned by fewer than one hundred persons within the meaning of Code Section 856(a)(5); (b) result in such Limited Partner or any other Person owning, directly or constructively under Code Section 856(d)(5), in excess of 9.9% of the total Shares (and any other ownership or beneficial interests) in the Trust; (c) cause more than 50% of the value of the Trust’s Shares (and any other ownership or beneficial interests) to be held by five or fewer individuals and certain organizations under Code Section 856(h) and 542(a)(2); (d) cause the Trust to own, directly or constructively, 10% or more of the ownership interests of any person that is a tenant with respect to any real property owned or constructively owned by the Trust (so as to prevent the application of Code Section 856(d)(2)); (e) cause the Trust to no longer qualify as a “domestically-controlled REIT” as defined in Code Section 897(h)(4) if the Trust is so qualified at the time of the proposed redemption; (f) cause the Trust to become a “Pension-Held REIT” as such term is defined in Code Section 856(h)(3) if the Trust was not a “Pension-Held REIT” immediately prior to the proposed redemption; or (g) cause the acquisition of Shares (and any other ownership or beneficial interests) in the Trust by such Limited Partner to be “integrated” with any other distribution of interests in the Trust for purposes of complying with the registration provisions of the Securities Act of 1933. The General Partner may modify the restrictions set forth in this Section 3.8(b) from time to time in its discretion to ensure that the Partnership complies and continues to comply with Code Section 856. The General Partner may, in its sole discretion, waive the restrictions on redemption set forth in this Section 3.8(b); provided , however , that in the event a restriction is waived, the applicable Redeeming Partner shall be paid the Cash Amount.

     (v) A Limited Partner shall not be entitled to exercise a Redemption Right if it prejudices or affects the continuity of the Partnership for purposes of Code Section 708. Prior to any such redemption, the General Partner may require an opinion of counsel, which counsel and opinion shall be satisfactory to the General Partner, to the effect that such redemption will not cause adverse tax consequences to the non-redeeming Partners, and such Limited Partner exercising the Redemption Right shall be responsible for paying said counsel’s fee for such opinion.

     (vi) The Partnership shall not redeem any Partnership Interests for the Cash Amount pursuant to this Section 3.8(a) requested to be redeemed pursuant to a Notice of Redemption that did not request a Liquidating Redemption, unless the Partnership and the Trust can also make, in accordance with Section 3.10, all Liquidating Redemptions requested to be made pursuant to Notices of Redemption then in effect that did request Liquidating Redemptions.

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     (c) Notwithstanding the provisions of Section 3.8(a), a Limited Partner that exercises the Redemption Right shall be deemed to have offered to sell the Partnership Interests described in the Notice of Redemption to the Trust, and the Trust (or any designee thereof) may, in its sole and absolute discretion, elect to purchase directly and acquire such Partnership Interests by paying to the Redeeming Partner either the Cash Amount or the REIT Shares Amount, as elected by the Trust or any designee thereof (each in its sole and absolute discretion), on the Specified Redemption Date, whereupon the Trust or any designee thereof shall acquire the Partnership Interests offered for redemption by the Redeeming Partner and shall be treated for all purposes of this Agreement as the owner of such Partnership Interests as of the Specified Redemption Date. If the Trust or any designee thereof shall elect to exercise its right to purchase Partnership Interests under this Section 3.8(c) with respect to a Notice of Redemption, it shall so notify the Redeeming Partner within five Business Days after the receipt by the General Partner of such Notice of Redemption. Unless the Trust or any designee thereof (each in its sole and absolute discretion) shall exercise its right to purchase Partnership Interests from the Redeeming Partner pursuant to this Section 3.8(c), neither the Trust nor any designee thereof shall have any obligation to the Redeeming Partner or the Partnership with respect to such Redeeming Partner’s exercise of such Redemption Right. In the event that the Trust or any designee thereof shall exercise its right to purchase Partnership Interests with respect to the exercise of a Redemption Right in the manner described in the first sentence of this Section 3.8(c), the Partnership shall have no obligation to pay any amount to the Redeeming Partner with respect to such Redeeming Partner’s exercise of such Redemption, and each of the Redeeming Partner, the Partnership, and the Trust or any designee thereof, as the case may be, shall treat the transaction between the Trust or its designee, as the case may be, and the Redeeming Partner for federal income tax purposes as a sale of the Redeeming Partner’s Partnership Interests to the Trust or such designee. Each Redeeming Partner agrees to execute such documents as the General Partner or the Trust may reasonably require in connection with the issuance of Shares equal to the REIT Shares Amount upon exercise of the Redemption Right by a Limited Partner and the election to purchase such Partnership Interests by the Trust. Notwithstanding the foregoing, the Trust may not elect, pursuant to this Section 3.8(c), to acquire Partnership Interests for the Cash Amount pursuant to any Notice of Redemption that did not request a Liquidating Redemption, unless the Trust and the Partnership can also make, in accordance with Section 3.10, all Liquidating Redemptions requested to be made pursuant to Notices of Redemption then in effect that did request Liquidating Redemptions.

     (d) The Trust shall at all times reserve and keep available out of its authorized but unissued Shares, solely for the purpose of effecting the exchange of Partnership Interests for Shares, a number of Snares equal to the number of Outstanding Unit Equivalents not owned by the Trust. No Limited Partner shall, by virtue of being the holder of a Partnership Interest be deemed to be a Shareholder of or have any other interest in the Trust. In the event of any change in the outstanding Shares of the Trust or its successor by reason of any share dividend, split, recapitalization, merger, consolidation, combination, exchange of shares or other similar corporate change other than the issuance of Rights, as further described in Section 3.8(e) (a “ Recapitalization ”), the number of OP Units held by each Partner shall be adjusted upward or downward to

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equal such number of Shares of the Trust (or as applicable, the Shares or equivalent class of securities of the successor thereto) as would have been held by the Partner immediately following the Recapitalization if such Partner had held a number of Shares equal to such number of OP Units immediately prior to such Recapitalization, In the event the Trust or any designee thereof acquires Participation Interests pursuant to Section 3.8(c), any Participation Interest so acquired shall be automatically converted into a number of OP Units which equals the REIT Shares Amount attributable to such Participation Interest, and the General Partner shall record the transfer on the books of the Partnership so that the Trust or any designee thereof, as applicable, is thereupon the owner and holder of such OP Units. As is more particularly described in Section 3.8(b)(iv), notwithstanding any other provisions of this Section 3.8, a Limited Partner shall not have the right to exercise a Redemption Right if, upon payment of the REIT Shares Amount to such Limited Partner, (i) the Trust would, as a result thereof, no longer qualify (or it would be reasonably possible in the judgment of the General Partner that the Trust no longer would qualify) as a real estate investment trust under the Code; or (ii) the payment of such REIT Shares Amount to the Limited Partner would constitute or be reasonably possible in the judgment of the General Partner to constitute a violation of applicable federal or state securities laws or would violate any applicable provisions of the organizational documents of the Trust (including without limitation any restrictions on ownership of securities of the Trust set forth in the Declaration of Trust or Bylaws of the Trust). In either such event, to the extent the consequences described in clause (i) or (ii) of the preceding sentence could be