UNDERWRITING AGREEMENT

Exhibit 1.1

EXECUTION VERSION

PROLOGIS

$500,000,000

2.625 % Convertible Senior Notes due 2038

Underwriting Agreement

dated May 1, 2008

Goldman, Sachs & Co.
Banc of America Securities LLC
Morgan Stanley & Co. Incorporated

Underwriting Agreement

May 1, 2008

GOLDMAN, SACHS & CO.
BANC OF AMERICA SECURITIES LLC
MORGAN STANLEY & CO. INCORPORATED

c/o Goldman, Sachs & Co.
85 Broad Street,
New York, New York 10004

Ladies and Gentlemen:

      Introductory. ProLogis, a Maryland real estate investment trust (the “ Company ”), proposes to issue and sell to each of you, as underwriters (the “ Underwriters ”), acting severally and not jointly, the respective amounts set forth in Schedule A hereto of $500,000,000 aggregate principal amount of the Company’s 2.625% Convertible Senior Notes due 2038 (the “ Firm Securities ”). The Company also proposes to issue and sell to the Underwriters not more than an additional $50,000,000 aggregate principal amount of the Company’s 2.625% Convertible Senior Notes due 2038 (the “ Additional Securities ”) if and to the extent that the Underwriters shall have determined to exercise the right to purchase such 2.625% Convertible Senior Notes due 2038 granted to the Underwriters in Section 2(a) hereof. The Firm Securities and the Additional Securities are hereinafter collectively referred to as the “ Securities ”. The Securities will be convertible into common shares of beneficial interest (the “ Underlying Securities ”) of the Company, par value $0.01 per share (the “ Common Stock ”).

     The Securities will be issued pursuant to an indenture, dated as of March 1, 1995 (the “ Base Indenture ”), between the Company (formerly Security Capital Industrial Trust) and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as trustee (the “ Trustee ”), as supplemented by the first supplemental indenture, dated as of February 9, 2005 (the “ First Supplemental Indenture ”), the second supplemental indenture, dated as of November 2, 2005 (the “ Second Supplemental Indenture ”), the third supplemental indenture, dated as of November 2, 2005 (the “ Third Supplemental Indenture ”), the fourth supplemental indenture, dated as of March 26, 2007 (the “ Fourth Supplemental Indenture ”), and the fifth supplemental indenture, dated as of November 8, 2007 (the “ Fifth Supplemental Indenture ”). Certain terms of the Securities will be established pursuant to a sixth supplemental indenture, adopted by the Company pursuant to Section 301 of the Base Indenture (the “ Sixth Supplemental Indenture ” and together with the Base Indenture, the First Supplemental Indenture, the Second Supplemental Indenture, the Third Supplemental Indenture, the Fourth Supplemental Indenture, and the Fifth Supplemental Indenture, the “ Indenture ”). The Securities will be issued in book-entry form in the name of Cede & Co., as nominee of The Depository Trust Company (the “Depositary”), pursuant to a Letter of Representations, to be dated as of the Closing Date (as defined in Section 2 below) (the “ DTC Agreement ”), between the Company and the Depositary.

     The Company has prepared and filed with the Securities and Exchange Commission (the “ Commission ”) a registration statement on Form S-3 (File No. 333-132616), which contains a base prospectus dated August 21, 2006 (the “ Base Prospectus ”), to be used in connection with the public offering and sale of debt securities, including the Securities, and other securities of the Company under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “ Securities Act ”), and the offering thereof from time to time in accordance with Rule 415 under the Securities Act. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, in the form in which it became effective under the Securities Act, including any required information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430B under the Securities Act, is called the “Registration Statement.” The term “ Prospectus ” shall mean the final prospectus supplement relating to the Securities, together with the Base Prospectus, that is first filed pursuant to Rule 424(b) after the date and time that this Agreement is executed and delivered by the parties hereto. The term “ Preliminary Prospectus ” shall mean any preliminary prospectus supplement relating to the Securities, together with the Base Prospectus, that is first filed with the Commission pursuant to Rule 424(b). Any reference herein to the Registration Statement, the Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents that are or are deemed to be incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act prior to 4:45 p.m. Eastern Daylight Time on May 1, 2008 (the “ Initial Sale Time ”). All references in this Agreement to the Registration Statement, the Preliminary Prospectus, the Prospectus, or any amendments or supplements to any of the foregoing, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“ EDGAR ”).

     All references in this Agreement to financial statements and schedules and other information which is “disclosed,” “contained,” “included” or “stated” (or other references of like import) in the Registration Statement, Preliminary Prospectus or Prospectus shall be deemed to mean and include all such financial statements and schedules and other information which is or is deemed to be incorporated by reference in the Registration Statement, Preliminary Prospectus or Prospectus, as the case may be, prior to the Initial Sale Time; and all references in this Agreement to amendments or supplements to the Registration Statement, Preliminary Prospectus or Prospectus shall be deemed to include the filing of any document under the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), which is or is deemed to be incorporated by reference in the Registration Statement, Preliminary Prospectus or Prospectus, as the case may be, after the Initial Sale Time.

     The Securities, together with certain other senior indebtedness of the Company, will have the benefit of a pledge of certain collateral (the “ Collateral ”) pursuant to (i) that certain Second Amended and Restated Borrower Pledge Agreement dated as of October 6, 2005 (the “ Borrower Pledge Agreement ”) executed by the Company and Bank of America, N.A., as collateral agent (the “ Collateral Agent ”); (ii) each of the separate Subsidiary Pledge Agreements dated as of October 6, 2005 (collectively, the “ Subsidiary Pledge Agreements ”; and, together with the Borrower Pledge Agreement, the “ U.S. Pledge Agreements ”) executed by the Collateral Agent and each of ProLogis Japan Finance Incorporated, ProLogis Japan Incorporated, ProLogis Development Services Incorporated, ProLogis Management Incorporated, ProLogis-North Carolina (2) Incorporated, ProLogis-Monterrey (1) LLC, ProLogis-Monterrey (2) LLC, ProLogis-Reynosa (1) LLC, ProLogis-Reynosa (2) LLC (such entities being the “ U.S.

Grantors ”), ProLogis KK (the “ Japanese Grantor ”), ProLogis China Holding II Srl. (the “ Barbados Grantor ”); and (iii) that certain Pledge of Intercompany Receivables dated as of October 6, 2005 executed by PLD Europe Finance B.V., ProLogis UK Funding B.V., ProLogis UK Finding II B.V. (such entities being the “Dutch Grantors”; and, together with the Japanese Grantor and the Barbados Grantor, the “ Foreign Grantors ”; and, together with the U.S. Grantors, the Japanese Grantor and the Barbados Grantor, the “ Subsidiary Grantors ”; and the Subsidiary Grantors together with the Company, the “ Grantors ”), and the Collateral Agent (the “ Intercompany Pledge Agreement ”; and, together with the U.S. Pledge Agreements, the “ Pledge Agreements ”) The rights, duties, authority and responsibilities of the Collateral Agent and the relationship among the Credit Parties (which includes, without limitation, the holders of debt securities issued under the Indenture, including the Securities) regarding their pari passu interests in the collateral is governed by that certain Amended and Restated Security Agency Agreement, dated as of October 6, 2005 (the “ Security Agency Agreement ”) among the Company, Collateral Agent and Bank of America, N.A., as Global Administrative Agent (the “ Administrative Agent ”). The Security Agency Agreement, the Pledge Agreements and any related security documents are referred to herein collectively as the “ Security Documents .”

     The Company hereby confirms its agreements with the Underwriters as follows:

      Section 1. Representations and Warranties . The Company hereby represents, warrants and covenants to each Underwriter as of the date hereof, as of the Initial Sale Time and as of the Closing Date (in each case, a “ Representation Date ”), as follows:

     (a)  Compliance with Registration Requirements. The Company meets the requirements for use of Form S-3 under the Securities Act. The Registration Statement has become effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement has been issued under the Securities Act and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated or threatened by the Commission, and any request on the part of the Commission for additional or supplemental information has been complied with. In addition, the Indenture has been duly qualified under the Trust Indenture Act of 1939, as amended (the “ Trust Indenture Act ”).

     At the respective times the Registration Statement and any post-effective amendments thereto (including the filing of the Company’s most recent Annual Report on Form 10-K with the Commission (the “ Annual Report on Form 10-K ”)) became effective and at each Representation Date, the Registration Statement and any amendments thereto (i) complied and will comply in all material respects with the requirements of the Securities Act and the rules and regulations of the Commission thereunder (the “ Securities Act Regulations ”) and the Trust Indenture Act and the rules and regulations of the Commission thereunder, and (ii) did not and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. At the date of the Prospectus and at the Closing Date, neither the Preliminary Prospectus nor the Prospectus nor any amendments or supplements thereto included or will include an untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. Notwithstanding the foregoing, the representations and warranties in this subsection shall not apply to (i) that part of the

Registration Statement which constitutes the Statement of Eligibility on Form T-1 of the Trustee under the Trust Indenture Act (the “ Form T-1 ”) and (ii) statements in or omissions from the Registration Statement or any post-effective amendment or the Prospectus or any amendments or supplements thereto, made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter expressly for use therein.

     Each preliminary prospectus and prospectus filed as part of the Registration Statement, as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act Regulations and the Preliminary Prospectus and the Prospectus delivered to the Underwriters for use in connection with the offering of the Securities will, at the time of such delivery, be identical to any electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

     (b)  Disclosure Package . The term “Disclosure Package” shall mean (i) the Preliminary Prospectus, (ii) the issuer free writing prospectuses as defined in Rule 433 of the Securities Act (each, an “ Issuer Free Writing Prospectus ”), if any, identified in Annex I hereto and (iii) any other Issuer Free Writing Prospectus that the parties hereto shall hereafter expressly agree in writing to treat as part of the Disclosure Package. As of the Initial Sale Time, the Disclosure Package did not contain any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from the Disclosure Package based upon and in conformity with written information furnished to the Company by any Underwriter specifically for use therein.

     (c)  Incorporated Documents . The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus (i) at the time they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the Exchange Act and the rules and regulations of the Commission thereunder (the “ Exchange Act Regulations ”) and (ii) when read together with the other information in the Disclosure Package, at the Initial Sale Time, and when read together with the other information in the Prospectus, at the date of the Prospectus and at the Closing Date, did not and will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

     (d)  Company is a Well-Known Seasoned Issuer . (i) At the time of filing the Registration Statement, (ii) at the time of the most recent amendment thereto for the purposes of complying with Section 10(a)(3) of the Securities Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), (iii) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) of the Securities Act) made any offer relating to the Securities in reliance on the exemption of Rule 163 of the Securities Act, and (iv) as of the date hereof (the “ Execution Time ”), the Company was and is a “well known seasoned issuer” as defined in Rule 405 of the Securities Act. The Registration Statement is an “automatic shelf registration statement,” as defined in Rule 405 of the Securities Act, that initially became effective within three years of the Execution Time; the Company has not

received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form; and the Company has not otherwise ceased to be eligible to use the automatic shelf registration statement form.

     (e)  Company is not an Ineligible Issuer . (i) At the earliest time after the filing of the Registration Statement when a bona fide offer (as used in Rule 164(h)(2) of the Securities Act Regulations) of the Securities is first made by the Company or any other offering participant, and (ii) as of the Execution Time, the Company was not and is not an Ineligible Issuer (as defined in Rule 405 of the Securities Act).

     (f)  Issuer Free Writing Prospectuses . Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Securities or until any earlier date of which the Company notified or notifies the Underwriters, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, the Preliminary Prospectus or the Prospectus, including any document incorporated by reference therein that has not been superseded or modified. The foregoing sentence does not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Company by any Underwriter specifically for use therein.

     (g)  Distribution of Offering Material by the Company. The Company has not distributed and will not distribute, prior to the later of the Closing Date or Optional Closing Date, if any, and the completion of the Underwriters’ distribution of the Securities, any offering material in connection with the offering and sale of the Securities other than the Preliminary Prospectus, the Prospectus, and any Issuer Free Writing Prospectus reviewed and consented to by the Underwriters and identified in Annex I hereto.

     (h)  The Underwriting Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

     (i)  Authorization of the Base Indenture . The Base Indenture has been duly qualified under the Trust Indenture Act and has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement of the Company, enforceable against the Company in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

     (j)  Authorization of the Supplemental Indentures. Each of the First Supplemental Indenture, the Second Supplemental Indenture, the Third Supplemental Indenture, the Fourth Supplemental Indenture, and the Fifth Supplemental Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement of the Company, enforceable against the Company in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles. The Sixth Supplemental Indenture has been duly authorized by the Company and, at the Closing Date, will have been duly executed and delivered by the Company and, assuming due execution and delivery by the Trustee, will constitute a valid

and binding agreement of the Company, enforceable against the Company in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

     (k)  Authorization of the Securities. The Securities to be purchased by the Underwriters from the Company are in the form contemplated by the Indenture, have been duly authorized for issuance and sale pursuant to this Agreement and the Indenture and, at the Closing Date, will have been duly executed by the Company and, when authenticated in the manner provided for in the Indenture and delivered against payment of the purchase price therefor, will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles, and will be entitled to the benefits of the Indenture.

     (l)  The Underlying Securities . Upon issuance and delivery of the Securities in accordance with this Agreement and the Indenture, the Securities will be convertible at the option of the holder thereof into the Underlying Securities, cash or a combination thereof as determined by the Company in accordance the terms of the Securities; the Underlying Securities reserved for issuance upon conversion of the Securities have been duly authorized and reserved and, if and when issued upon conversion of the Securities in accordance with the terms of the Securities, will be validly issued, fully paid and non assessable, and the issuance of the Underlying Securities will not be subject to any preemptive or similar rights.

     (m)  Authorization of the Pledge Agreements . Each of the Pledge Agreements has been duly authorized, executed and delivered by the respective Grantor and constitutes a valid and binding agreement of such Grantor, enforceable against it in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

     (n)  Creation of Security Interest . The representations and warranties of each of the Grantors contained in the respective Pledge Agreement are true and correct with the same force and effect as if expressly made herein as of the date hereof. The Grantors are the legal and beneficial owners of the Collateral free and clean of any lien, except for the liens and security interests created under the Security Documents.

     (o)  Description of the Securities, the Underlying Securities, the Indenture and the Security Documents . The Securities, the Underlying Securities, the Indenture and the Security Documents conform in all material respects to the descriptions thereof contained in the Disclosure Package and the Prospectus.

     (p)  No Material Adverse Change . Except as otherwise disclosed in the Disclosure Package and the Prospectus, subsequent to the respective dates as of which information is given in the Disclosure Package and the Prospectus: (i) there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the

condition, financial or otherwise, or in the earnings, business, operations or prospects, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change is called a “ Material Adverse Change ”); (ii) the Company and its subsidiaries, considered as one entity, have not incurred any material liability or obligation, indirect, direct or contingent, not in the ordinary course of business or entered into any material transaction or agreement not in the ordinary course of business; and (iii) except for regular quarterly dividends on the common stock or shares or preferred stock or shares in amounts per share that are consistent with past practice, there has been no dividend or distribution of any kind declared, paid or made by the Company or, except for dividends paid to the Company or other subsidiaries, any of its subsidiaries on any class of capital stock or shares or repurchase or redemption by the Company or any of its subsidiaries of any class of capital stock or shares.

     (q)  Independent Accountants. KPMG LLP, who have expressed their opinion with respect to the Company’s audited financial statements for the fiscal years ended December 31, 2005, 2006 and 2007 incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus, are independent public or certified public accountants within the meaning of Regulation S-X under the Securities Act and the Exchange Act and a registered public accounting firm within the meaning of the Sarbanes-Oxley Act of 2002.

     (r)  Preparation of the Financial Statements. The financial statements together with the related notes thereto and the related schedule incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus present fairly the consolidated financial position of the Company and its subsidiaries, as of and at the dates indicated and the results of their operations and cash flows for the periods specified. Such financial statements and related schedule have been prepared in conformity with generally accepted accounting principles as applied in the United States applied on a consistent basis throughout the periods involved, except as may be expressly stated in the related notes thereto. No other financial statements or supporting schedules are required to be included in the Registration Statement. The summary financial information included in the Preliminary Prospectus and the Prospectus present fairly in all material respects the information shown therein and have been compiled on a basis consistent with that of the audited financial statements incorporated by reference in the Registration Statement, the Preliminary Prospectus and the Prospectus.

     (s)  Incorporation and Good Standing of the Company. The Company has been duly organized and is validly existing as a real estate investment trust in good standing under the laws of the State of Maryland and has the trust power and authority to own, lease and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus, and to enter into and perform its obligations under each of this Agreement, the Securities, the Indenture and the Borrower Pledge Agreement. The Company is duly qualified to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except for such jurisdictions where the failure to so qualify or to be in good standing would not, individually or in the aggregate, result in a Material Adverse Change.

     (t)  Incorporation and Good Standing of the Subsidiary Grantors. Each of the Subsidiary Grantors has been duly incorporated and is validly existing and, to the extent

applicable in such jurisdiction, in good standing under the laws of its jurisdiction of organization and has the power and authority to own, lease and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus, and to enter into and perform its obligations under the respective Pledge Agreement. Each Subsidiary Grantor is duly qualified to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except for such jurisdictions where the failure to so qualify or to be in good standing would not, individually or in the aggregate, result in a Material Adverse Change.

     (u)  Incorporation and Good Standing of Significant Subsidiaries. Each subsidiary and joint venture of the Company listed on Schedule B hereto (collectively, the “ Significant Subsidiaries ”) has been duly incorporated or organized, as the case may be, and is validly existing as a corporation, trust or partnership and (except as to any general partnership) in good standing under the laws of the jurisdiction of its incorporation or organization, as the case may be, and has the power (corporate or other) and authority to own, lease and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus. Each Significant Subsidiary is duly qualified as a foreign corporation, trust or partnership to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except for such jurisdictions where the failure to so qualify or to be in good standing would not, individually or in the aggregate, result in a Material Adverse Change. All of the issued and outstanding capital stock and other equity interests of each Significant Subsidiary have been duly authorized and validly issued, and are fully paid and (except for general partnership interests and directors’ qualifying shares) nonassessable; all shares of outstanding capital stock and other equity interests of each Significant Subsidiary held by the Company, directly or through subsidiaries, are owned free and clear of any security interest, mortgage, pledge, lien, encumbrance or claim, except for the pledge of such capital stock or other interests to secure borrowings of the Company or one of its wholly owned subsidiaries. The subsidiaries of the Company listed on Schedule B are the only subsidiaries of the Company that are material to the condition, financial or otherwise, or the earnings, business, operations or prospects of the Company and its subsidiaries, considered as one entity, and include all subsidiaries of the Company, which individually meet the criteria in the definition of “significant subsidiary” pursuant to Rule 1-02(w) of Regulation S-X under the Securities Act.

     (v)  Capital Stock Matters. All of the issued and outstanding shares of beneficial interest of the Company have been duly authorized and validly issued, are fully paid and nonassessable and have been issued in compliance with federal and state securities laws.

     (w)  Capitalization . The Company has an authorized capitalization as set forth in the Disclosure Package and the Prospectus under the heading “Capitalization”; there are no outstanding options to purchase, or any rights or warrants to subscribe for, or any securities or obligations convertible into, or any contracts or commitments to issue or sell, any shares of Common Stock, any shares of capital stock of any subsidiary, or any such warrants, convertible securities or obligations, except as set forth in the Disclosure Package and the Prospectus and except for options granted under, or contracts or commitments pursuant to, the Company’s previous or currently existing option and other similar officer, trustee or employee benefit plans; and there are no contracts, commitments, agreements, arrangements, understandings or

undertakings of any kind to which the Company is a party, or by which it is bound, granting to any person the right to require either the Company to file a registration statement under the Securities Act with respect to any securities of the Company or requiring the Company to include such securities with the Securities registered pursuant to any registration statement, except as set forth in the Disclosure Package and the Prospectus.

     (x)  Non-Contravention of Existing Instruments; No Further Authorizations or Approvals Required. Neither the Company nor any of its subsidiaries is in violation of its declaration of trust (or charter or by-laws or other similar constitutive documents), except, in the case of subsidiaries of the Company, for such violations as would not, individually or in the aggregate, result in a Material Adverse Change. Neither the Company nor any of its subsidiaries is in default (or, with the giving of notice or lapse of time or both, would be in default) (“ Default ”) under any indenture, mortgage, loan or credit agreement, note, contract, franchise, lease or other instrument to which the Company or any of its subsidiaries is a party or by which it or any of them may be bound, including the Security Documents, or to which any of the property or assets of the Company or any of its subsidiaries is subject (each, an “ Existing Instrument ”), except for such Defaults as would not, individually or in the aggregate, result in a Material Adverse Change. The Company’s execution, delivery and performance of this Agreement and the Indenture, and the issuance and delivery of the Securities (including the issuance of the Underlying Securities upon conversion thereof), the consummation of the transactions contemplated hereby or thereby and by the Disclosure Package and the Prospectus and the Grantors’ execution, delivery and performance of the Pledge Agreements (i) have been duly authorized by all necessary trust, corporate or other action, as the case may be, and will not result in any violation of the provisions of the declaration of trust (or charter or by-laws or other similar constitutive documents) of the Grantors or any subsidiary of the Company, except, in the case of subsidiaries of the Company, for such violations as would not, individually or in the aggregate, result in a Material Adverse Change, (ii) will not conflict with or constitute a breach of, or Default under, or result in the creation or imposition of any lien, charge or encumbrance (other than the lien, charge or encumbrance created by the Pledge Agreements in favor of the Collateral Agent) upon any property or assets of the Grantors or any of their subsidiaries pursuant to, or require the consent of any other party to, any Existing Instrument, except for such conflicts, breaches, Defaults, liens, charges or encumbrances as would not, individually or in the aggregate, result in a Material Adverse Change and (iii) will not result in any violation of any law, administrative regulation or administrative or court decree applicable to the Grantors or any subsidiary of the Company, except for such violation as would not, individually or in the aggregate, result in a Material Adverse Change. No consent, approval, authorization or other order of, or registration or filing with, any court or other governmental or regulatory authority or agency, is required for the Company’s execution, delivery and performance of this Agreement or the Indenture, or the issuance and delivery of the Securities (including the issuance of the Underlying Securities upon conversion thereof) or consummation of the transactions contemplated hereby or thereby and by the Disclosure Package and the Prospectus, or the Grantors’ execution, delivery and performance of the Pledge Agreements, except such as have been obtained or made by the Company or the Grantors and are in full force and effect under the Securities Act, the Trust Indenture Act and applicable state securities or blue sky laws and from the Financial Industry Regulatory Authority (“ FINRA ”) or the failure of which to obtain would not result in a Material Adverse Change or have a material adverse effect on the consummation of the transactions contemplated by this Agreement.

     (y)  No Material Actions or Proceedings. Except as otherwise disclosed in the Disclosure Package and the Prospectus, there are no legal or governmental actions, suits or proceedings pending or, to the best of the Company’s knowledge, threatened (i) against or affecting the Company or any of its subsidiaries, (ii) which has as the subject thereof any officer or director of, or property owned or leased by, the Company or any of its subsidiaries or (iii) relating to environmental or discrimination matters, where in any such case (A) there is a reasonable possibility that such action, suit or proceeding might be determined adversely to the Company or such subsidiary and (B) any such action, suit or proceeding, if so determined adversely, would reasonably be expected to result in a Material Adverse Change or adversely affect the consummation of the transactions contemplated by this Agreement.

     (z)  Labor Matters. No material labor dispute with the employees of the Company or any of its subsidiaries exists or, to the best of the Company’s knowledge, is threatened or imminent, except for such disputes as would not, individually or in the aggregate, result in a Material Adverse Change.

     (aa)  Intellectual Property Rights. The Company and its subsidiaries own or possess sufficient trademarks, trade names, patent rights, copyrights, domain names, licenses, approvals, trade secrets and other similar rights (collectively, “ Intellectual Property Rights ”) reasonably necessary to conduct their businesses as now conducted, except as would not result in a Material Adverse Change; and the expected expiration of any of such Intellectual Property Rights would not result in a Material Adverse Change. Neither the Company nor any of its subsidiaries has received any notice of infringement or conflict with asserted Intellectual Property Rights of others, which infringement or conflict, if the subject of an unfavorable decision, would result in a Material Adverse Change. The Company is not a party to or bound by any options, licenses or agreements with respect to the Intellectual Property Rights of any other person or entity that are required to be set forth in the Registration Statement, the Preliminary Prospectus or the Prospectus, and that are not described in all material respects in such documents. None of the technology employed by the Company has been obtained or is being used by the Company in violation of any contractual obligation binding on the Company or, to the Company’s knowledge, any of its officers, directors or employees or otherwise in violation of the rights of any persons, except for such violations as would not, individually or in the aggregate, result in a Material Adverse Change.

     (bb)  All Necessary Permits, etc. The Company and each subsidiary possess such valid and current certificates, authorizations, permits, licenses, approvals, consents and other authorizations issued by the appropriate state, federal or foreign regulatory agencies or bodies necessary to conduct their respective businesses, and neither the Company nor any subsidiary has received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such certificate, authorization, permit, license, approval, consent or other authorization which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, could result in a Material Adverse Change.

     (cc)  Title to Properties. Except as otherwise disclosed in the Disclosure Package and the Prospectus, the Company and each of its subsidiaries has good and marketable title to all the properties and assets reflected as owned in the financial statements referred to in Section 1(r) above (or elsewhere in the Disclosure Package and the Prospectus), in each case free and clear of

any security interests, mortgages, liens, encumbrances, equities, claims and other defects, except such as do not materially and adversely affect the value of such property and do not materially interfere with the use made or proposed to be made of such property by the Company or such subsidiary. The real property, improvements, equipment and personal property held under lease by the Company or any subsidiary are held under valid and enforceable leases, with such exceptions as are not material and do not materially interfere with the use made or proposed to be made of such real property, improvements, equipment or personal property by the Company or such subsidiary.

     (dd)  Tax Law Compliance. The Company and its subsidiaries have filed all material federal, state and foreign income and franchise tax returns or have properly requested extensions thereof and have paid all taxes required to be paid by any of them and, if due and payable, any related or similar assessment, fine or penalty levied against any of them except as may be being contested in good faith and by appropriate proceedings. The Company has made adequate charges, accruals and reserves in the applicable financial statements referred to in Section 1(r) above in respect of all federal, state and foreign income and franchise taxes for all periods as to which the tax liability of the Company or any of its subsidiaries has not been finally determined. With respect to all tax periods in respect of which the Internal Revenue Service is or will be entitled to any claim, the Company has met the requirements for qualification as a real estate investment trust under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended, and the regulations and published interpretations thereunder (the “ Internal Revenue Code ”) and the Company’s present and contemplated organizational ownership, method of operation, assets and income are such that the Company will continue to meet such requirements.

     (ee)  Company Not an “Investment Company.” The Company is not, and after receipt of payment for the Securities and the application of the proceeds as described in the Disclosure Package and the Prospectus under “Use of Proceeds” will not be, an “investment company” within the meaning of the Investment Company Act of 1940, as amended (the “ Investment Company Act ”).

     (ff)  Insurance. Each of the Company and its subsidiaries taken as a whole carry or are covered by insurance in such amounts covering such risks as are generally deemed adequate and customary for their businesses. The Company has no reason to believe that it or any subsidiary will not be able (i) to renew its existing insurance coverage as and when such policies expire or (ii) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not result in a Material Adverse Change.

     (gg)  No Price Stabilization or Manipulation. The Company has not taken and will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities.

     (hh)  No Unlawful Contributions or Other Payments. Neither the Company nor any of its Significant Subsidiaries nor, to the best of the Company’s knowledge, any employee or agent of the Company or any Significant Subsidiary, has made any contribution or other payment to any official of, or candidate for, any federal, state or foreign office in violation of any law or of

the character necessary to be disclosed in the Disclosure Package and the Prospectus in order to make the statements therein, in the light of the circumstances under which such statements were made, not misleading.

     (ii)  Compliance with Environmental Laws. Except as would not, individually or in the aggregate, result in a Material Adverse Change (i) neither the Company nor any of its subsidiaries is in violation of any federal, state, local or foreign law or regulation relating to pollution or protection of human health or the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including without limitation, laws and regulations relating to emissions, discharges, releases or threatened releases of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum and petroleum products (collectively, “ Materials of Environmental Concern ”), or otherwise relating to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Materials of Environmental Concern (collectively, “ Environmental Laws ”), which violation includes, but is not limited to, noncompliance with any permits or other governmental authorizations required for the operation of the business of the Company or its subsidiaries under applicable Environmental Laws, or noncompliance with the terms and conditions thereof, nor has the Company or any of its subsidiaries received any written communication, whether from a governmental authority, citizens group, employee or otherwise, that alleges that the Company or any of its subsidiaries is in violation of any Environmental Law; (ii) there is no claim, action or cause of action filed with a court or governmental authority with respect to which the Company has received written notice, no investigation with respect to which the Company has received written notice, and no written notice by any person or entity alleging potential liability for investigatory costs, cleanup costs, governmental responses costs, natural resources damages, property damages, personal injuries, attorneys’ fees or penalties arising out of, based on or resulting from the presence, or release into the environment, of any Material of Environmental Concern at any location owned, leased or operated by the Company or any of its subsidiaries, now or in the past (collectively, “ Environmental Claims ”), pending or, to the best of the Company’s knowledge, threatened against the Company or any of its subsidiaries or any person or entity whose liability for any Environmental Claim the Company or any of its subsidiaries has retained or assumed either contractually or by operation of law; and (iii) to the best of the Company’s knowledge, there are no past or present actions, activities, circumstances, conditions, events or incidents, including, without limitation, the release, emission, discharge, presence or disposal of any Material of Environmental Concern, that reasonably could result in a violation of any Environmental Law or form the basis of a potential Environmental Claim against the Company or any of its subsidiaries or against any person or entity whose liability for any Environmental Claim the Company or any of its subsidiaries has retained or assumed either contractually or by operation of law.

     (jj)  ERISA Compliance. The Company and its subsidiaries and any “employee benefit plan” (as defined in Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended, and the regulations and published interpretations thereunder (collectively, “ ERISA ”)) established or maintained by the Company, its subsidiaries or their “ERISA Affiliates” (as defined below) are in compliance in all material respects with ERISA. “ ERISA Affiliate ” means, with respect to the Company or a subsidiary, any member of any group of organizations described in Sections 414(b), (c), (m) or (o) of the Internal Revenue Code, of which the Company or such subsidiary is a member. No “reportable event” (as defined under

ERISA) has occurred or is reasonably expected to occur with respect to any “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates. No “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates, if such “employee benefit plan” were terminated, would have any “amount of unfunded benefit liabilities” (as defined under ERISA). Neither the Company, its subsidiaries nor any of their ERISA Affiliates has incurred or reasonably expects to incur any liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any “employee benefit plan,” (ii) Sections 412, 4971 or 4975 of the Internal Revenue Code, or (iii) Section 4980B of the Internal Revenue Code with respect to the excise tax imposed thereunder. Each “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates that is intended to be qualified under Section 401(a) of the Internal Revenue Code has received a favorable determination letter from the Internal Revenue Service and nothing has occurred, whether by action or failure to act, which is reasonably likely to cause disqualification of any such employee benefit plan under Section 401(a) of the Internal Revenue Code.

     (kk)  Company’s Accounting System. The Company and its subsidiaries maintain effective internal control over financial reporting, as such term is defined in Rule 13a-15(f) under the Exchange Act.

     (ll)  Disclosure Controls and Procedures . The Company has established and maintains disclosure controls and procedures (as such term is defined in Rules 13a-15 and 15d-14 under the Exchange Act); such disclosure controls and procedures are designed to ensure that material information relating to the Company and its subsidiaries is made known to the chief executive officer and chief financial officer of the Company by others within the Company or any of its subsidiaries, and such disclosure controls and procedures are reasonably effective to perform the functions for which they were established subject to the limitations of any such control system; the Company’s auditors and the audit committee of the board of directors of the Company have been advised of: (i) any significant deficiencies or material weaknesses in the design or operation of internal controls which could adversely affect the Company’s ability to record, process, summarize, and report financial data; and (ii) any fraud, whether or not material, that involves management or other employees who have a role in the Company’s internal controls; and since the date of the most recent evaluation of such disclosure controls and procedures, there have been no significant changes in internal controls or in other factors that could significantly affect internal controls, including any corrective actions with regard to significant deficiencies and material weaknesses.

     Any certificate signed by any officer of the Company or any of its subsidiaries and delivered to the Underwriters or to counsel for the Underwriters in connection with the offering of the Securities shall be deemed a representation and warranty by the Company to each Underwriter as to the matters set forth therein on the date of such certificate and, unless subsequently amended or supplemented, at each Representation Date subsequent thereto.

     The Company acknowledges that the Underwriters and, for purposes of the opinions to be delivered pursuant to Section 5 hereof, counsel for the Company and counsel for the Underwriters, will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

      Section 2. Purchase, Sale and Delivery of the Securities.

     (a)  The Securities. The Company agrees to issue and sell to the several Underwriters, severally and not jointly, all of the Firm Securities upon the terms herein set forth. On the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Underwriters agree, severally and not jointly, to purchase from the Company the aggregate principal amount of Firm Securities set forth opposite their names on Schedule A at a purchase price of 98.00% of the principal amount of the 2.625% Convertible Senior Notes due 2038 (the “ Purchase Price ”), payable on the Closing Date (as defined below).

     On the basis of the representations, warranties and warranties contained in this Agreement, and subject to its terms and conditions, the Company agrees to issue and sell to the several Underwriters, severally and not jointly, the Additional Securities, and the Underwriters shall have the right to purchase in whole, or from time to time in part, up to $50,000,000 aggregate principal amount of Additional Securities at the Purchase Price plus accrued interest, if any, from the Closing Date (as defined in Section 2(b) hereof) to the date of payment and delivery. The Underwriters may exercise this right in whole or from time to time in part by giving written notice of each election to exercise this option not later than 30 days after the Closing Date. Any exercise notice shall specify the number of Additional Securities to be purchased by the Underwriters and the date on which such Additional Securities are to be purchased. Each purchase date must be at least one business day after the written notice is given and may not be earlier than the Closing Date nor later than ten business days after the date of such notice. Additional Securities may be purchased as provided in this Section 2 solely for the purpose of covering over-allotments made in connection with the offering of the Firm Securities. On the Optional Closing Date (as defined below) if any, each Underwriter agrees, severally and not jointly, to purchase the number of Additional Securities that bears the same proportion to the total number of Firm Securities to be purchased on such Optional Closing Date as the number of Firm Securities set forth in Schedule A opposite the name of such Underwriter bears to the total number of Additional Securities.

     (b)  The Closing Date and Optional Closing Date(s). Delivery of certificates for the Firm Securities in global form to be purchased by the Underwriters and payment therefor shall be made at the offices of Shearman & Sterling LLP (or such other place as may be agreed to by the Company and the Underwriters) at 9:00 a.m., New York City time, on May 7, 2008, or such other time and date as the Underwriters shall designate by notice to the Company (the time and date of such closing are called the “ Closing Date ”).

     Payment for and delivery of certificates for the Additional Securities will be made at the offices of Shearman & Sterling LLP (or such other place as may be agreed to by the Company and the Underwriters) at 9:00 a.m., New York City time, on the Closing Date or at such other time or place on the same or such other date, not later than June 6, 2008, as the Underwriters and the Company may agree upon in writing (the time and date of such payment and delivery is referred to herein as the “ Optional Closing Date ”).

     (c)  Public Offering of the Securities. The Underwriters hereby advise the Company that they intend to offer the Securities for sale to the public, as described in the Disclosure

Package and the Prospectus, as soon after this Agreement has been executed as the Underwriters, in their sole judgment, have determined is advisable and practicable.

     (d)  Payment for the Securities. Payment for the Securities shall be made at the Closing Date by wire transfer of immediately available funds to the order of the Company.

     It is understood that the Underwriters have been authorized to accept delivery of and receipt for, and make payment of the purchase price for, the Securities that they have agreed to purchase. The Underwriters may (but shall not be obligated to) make payment for any Securities to be purchased by any Underwriter whose funds shall not have been received by the Underwriters by the Closing Date for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

     (e)  Delivery of the Securities. The Company shall deliver, or cause to be delivered, to the Underwriters the Firm Securities at the Closing Date, and the Additional Securities at the Optional Closing Date, if any, against the irrevocable release of a wire transfer of immediately available funds for the amount of the purchase price therefor. The Firm Securities, and, if applicable, the Additional Securities, shall be in such denominations and registered in such names and denominations as the Underwriters shall have requested at least two full business days prior to the Closing Date or the Optional Closing Date, as the case may be, and shall be made available for inspection on the business day preceding the Closing Date or the Optional Closing Date, as the case may be, at a location in New York City, as the Underwriters may designate. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriters.

      Section 3. Additional Covenants. The Company further covenants and agrees with each Underwriter as follows:

     (a)  Compliance with Securities Regulations and Commission Requests. The Company, subject to Section 3(b), will comply with the requirements of Rule 430B of the Securities Act Regulations, and will promptly notify the Underwriters, and confirm the notice in writing, of (i) the effectiveness of any post-effective amendment to the Registration Statement or the filing of any supplement or amendment to the Preliminary Prospectus or the Prospectus, (ii) the receipt of any comments from the Commission during the Prospectus Delivery Period (defined below), (iii) any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Preliminary Prospectus or the Prospectus or for additional information, and (iv) the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order preventing or suspending the use of the Preliminary Prospectus or the Prospectus, or of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes. The Company will promptly effect the filings necessary pursuant to Rule 424 and will take such steps as it deems necessary to ascertain promptly whether the Preliminary Prospectus and the Prospectus transmitted for filing under Rule 424 was received for filing by the Commission and, in the event that it was not, it will promptly file such document. The Company will use its best efforts to prevent the issuance of any stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

     (b)  Filing of Amendments. During such period beginning on the date of this Agreement and ending on the later of the Closing Date or such date as, in the opinion of counsel for the Underwriters, the Prospectus is no longer required by law to be delivered in connection with sales of the Securities by an Underwriter or dealer, including in circumstances where such requirement may be satisfied pursuant to Rule 172 of the Securities Act Regulations (the “ Prospectus Delivery Period ”), the Company will give the Underwriters notice of its intention to file or prepare any amendment to the Registration Statement (including any filing under Rule 462(b) of the Securities Act Regulations), or any amendment, supplement or revision to the Disclosure Package or the Prospectus, whether pursuant to the Securities Act, the Exchange Act or otherwise, will furnish the Underwriters with copies of any such documents a reasonable amount of time prior to such proposed