SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): MAY 25, 1999 BOSTON PROPERTIES, INC. (Exact name of Registrant as specified in its charter) DELAWARE 1-13087 04-2473675 (State or other jurisdiction (Commission File (I.R.S. Employer of incorporation) Number) Identification No.) 800 BOYLSTON STREET, SUITE 400 BOSTON, MASSACHUSETTS 02199 (Address of principal executive offices and zip code) Registrant's telephone number, including area code: 617-236-3300

ITEM 5. OTHER EVENTS. On May 25, 1999, Boston Properties, Inc. (the "Company") completed the offering of 4,000,000 shares (the "Shares") of common stock, par value $.01 per share, resulting in net proceeds to the Company, after anticipated issuance costs, of approximately $141.0 million. The offering of the Shares was made pursuant to a Prospectus Supplement dated May 20, 1999 relating to the Prospectus dated January 29, 1999 filed with the Company's shelf registration statement on Form S-3 (File No. 333-69375). Goldman, Sachs & Co. acted as sole underwriter. The net proceeds of the offering will be used to reduce indebtedness under the Company's line of credit to provide additional capacity to fund its current and anticipated development activities. ITEM 7. FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS. (a) FINANCIAL STATEMENTS OF BUSINESS ACQUIRED: Not Applicable (b) PRO FORMA FINANCIAL INFORMATION: Not Applicable (c) EXHIBITS: EXHIBIT NO. 1. Underwriting Agreement dated as of May 20, 1999. 5. Opinion as to the legality of the Shares. 2

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Date: May 25, 1999 BOSTON PROPERTIES, INC. /s/ David G. Gaw ------------------------------ By: David G. Gaw Chief Financial Officer 3

Exhibit 1 - -------------------------------------------------------------------------------- BOSTON PROPERTIES, INC. (a Delaware corporation) 4,000,000 Shares of Common Stock UNDERWRITING AGREEMENT Dated: May 20, 1999 - --------------------------------------------------------------------------------

BOSTON PROPERTIES, INC. (a Delaware corporation) 4,000,000 Shares of Common Stock (Par Value $ .01 Per Share) UNDERWRITING AGREEMENT May 20, 1999 GOLDMAN, SACHS & CO. 85 Broad Street New York, New York 10004 Ladies and Gentlemen: Boston Properties, Inc., a Delaware corporation (the "Company"), and Boston Properties Limited Partnership, a Delaware limited partnership (the "Operating Partnership"), each confirms its agreement with Goldman, Sachs & Co. (the "Under writer"), with respect to the issue and sale by the Company and the purchase by the Underwriter of 4,000,000 shares of Common Stock, par value $.01 per share, of the Company ("Common Stock"). The aforesaid 4,000,000 shares of Common Stock to be purchased by the Underwriter are hereinafter called the "Securities". The Company and the Operating Partnership each understand that the Underwriter proposes to make a public offering of the Securities as soon as the Underwriter deems advisable after this Agreement has been executed and delivered. The Company has filed with the Securities and Exchange Commission (the "Commission") a registration statement on Form S-3 (No. 333-69375) covering the registration of the Securities under the Securities Act of 1933, as amended (the "1933 Act"), including a related prospectus, which has become effective. The registration statement as amended at the time it became effective, or, if a post-effective amendment has been filed with respect thereto, as amended by such post-effective amendment at the time of its effectiveness (including in each case the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A under the 1933 Act), is hereinafter referred to as the "Registration Statement"; the

prospectus as supplemented by the prospectus supplement relating to the sale of the Securities by the Underwriter in the form first used to confirm sales of Securities is hereinafter referred to as the "Prospectus." Any reference in this Agreement to the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act, as of the effective date of the Registration Statement or the date of such preliminary prospectus or the Prospectus, as the case may be (it being understood that the several specific references in this Agreement to documents incorporated by reference in the Registration Statement or the Prospectus are for clarifying purposes only and are not meant to limit the inclusiveness of any other definition herein), and any reference to "amend," "amendment" or "supplement" with respect to the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to refer to and include any documents filed after such date under the Securities Exchange Act of 1934, as amended (the "1934 Act"), and the rules and regulations of the Commission thereunder that are deemed to be incorporated by reference therein. For purposes of this Agreement, all references to the Registration Statement, any preliminary prospectus, or the Prospectus or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system ("EDGAR"). SECTION 1. REPRESENTATIONS AND WARRANTIES. (a) REPRESENTATIONS AND WARRANTIES BY THE COMPANY. The Company and the Operating Partnership each severally represents and warrants to the Underwriter as of the date hereof, and as of the Closing Time referred to in Section 2(b) hereof, and agrees with the Underwriter, as follows: (i) COMPLIANCE WITH REGISTRATION REQUIREMENTS. The Registration Statement has become effective under the 1933 Act and no stop order suspend ing the effectiveness of the Registration Statement has been issued under the 1933 Act and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated by the Commission, and any request on the part of the Commission for additional information has been complied with. At the respective times the Registration Statement and any post-effective amendments thereto became effective and at the Closing Time, the Registration Statement and any amendments and supplements thereto complied and will comply in all material respects with the requirements of the 1933 Act 2

and the 1933 Act Regulations and 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. Neither the Prospectus nor any amendment or supplement thereto, at the time the Prospectus or any amendment or supplement thereto was issued and at the Closing Time, 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 light of the circumstances under which they were made, not misleading. The representations and warranties in this subsection shall not apply to statements in or omissions from the Registration Statement or the Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by the Underwriter expressly for use in the Registration Statement or the Prospectus. Each preliminary prospectus and the 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 1933 Act, complied when so filed in all material respects with the 1933 Act Regulations and the Prospectus delivered to the Underwriter for use in connection with this offering was identical to the electronically transmitted copies thereof filed with the Commis sion pursuant to EDGAR, except to the extent permitted by Regulation S-T. (ii) INDEPENDENT ACCOUNTANTS. The accountants who certified the financial statements and supporting schedules included or incorporated by reference in the Registration Statement are independent public accountants as required by the 1933 Act and the 1933 Act Regulations. (iii) FINANCIAL STATEMENTS. The consolidated and combined financial statements included or incorporated by reference in the Registration Statement and the Prospectus, together with the related schedules and notes, present fairly the financial position of the Company and its Predecessor Group (as defined in the Registration Statement) at the dates indicated, and the consolidated and combined statements of operations, owners' equity and cash flows of the Company and the Predecessor Group for the periods specified; said financial statements have been prepared in conformity with generally accepted accounting principles ("GAAP") applied on a consistent basis throughout the periods involved. The supporting schedules included in the Registration Statement present fairly in accordance with GAAP the information required to be stated therein. The unaudited pro forma condensed consolidated financial statements and the related notes thereto included or incorporated by reference in the 3

Registration Statement and the Prospectus present fairly the information shown therein, have been prepared in accordance with the Commission's rules and guidelines with respect to pro forma financial statements and have been properly compiled on the bases described therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to therein. The selected financial data and the summary financial information included in the Prospectus present fairly the information shown therein and have been compiled on a basis consistent with that of the audited financial statements included or incorporated by reference in the Registration Statement. Other than the historical and pro forma financial statements (and schedules) included or incorporated by reference in the Registration Statement and Prospectus, no other historical or pro forma financial statements (or schedules) are required by the 1933 Act or the 1933 Act Regulations to be included therein. (iv) NO MATERIAL ADVERSE CHANGE IN BUSINESS. Since the respective dates as of which information is given in the Registration Statement and the Prospectus, except as otherwise stated therein or in documents incorporated by reference therein, (A) there has been no material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company, the Operating Partnership and the Subsidiaries (as hereinafter defined) considered as one enterprise, whether or not arising in the ordinary course of business (a "Material Adverse Effect"), (B) no material casualty loss or material condemnation or other material adverse event with respect to any of the properties set forth in Schedule B hereto has occurred, (C) there have been no transactions entered into by the Company, the Operating Partnership or any of the Subsidiaries, other than those in the ordinary course of business, which are material with respect to the Company, the Operating Partnership and the Subsidiaries considered as one enterprise, and (D) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock or by the Operating Partnership or any of its Subsidiaries with respect to its partnership interests or any class of its capital stock. (v) GOOD STANDING OF THE COMPANY. The Company has been duly organized and is validly existing as a corporation in good standing under the laws of the State of Delaware and has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Prospectus and to enter into and perform its obligations under this Agreement; and the Company is duly qualified as a foreign corporation to transact business 4

and is in good standing in each other jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect. (vi) GOOD STANDING OF SUBSIDIARIES. Each of the subsidiaries of the Company, including without limitation the Operating Partnership (each a "Subsidiary" and, collectively, the "Subsidiaries"), has been duly organized and is validly existing as a general or limited partnership or corporation, as the case may be, in good standing (in the case of corporations and limited partnerships) under the laws of the jurisdiction of its organization, has partnership or corporate power and authority, as the case may be, to own, lease and operate its properties and to conduct its business as described in the Prospectus and is duly qualified as a foreign partnership or corporation 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 where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect; all of the issued and outstanding capital stock of each of the Subsidiaries that is a corporation has been duly authorized and validly issued, is fully paid and non-assessable, and all of the partnership interests in each Subsidiary that is a partnership are validly issued and fully paid; except as otherwise disclosed in the Registration Statement, all such shares and interests, as the case may be, are owned by the Company, directly or through Subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity; none of the outstanding shares of capital stock or partnership interests of any Subsidiary was issued in violation of the preemptive or similar rights of any securityholder of such Subsidiary. (vii) CAPITALIZATION. The authorized capital stock of the Company is, and the issued and outstanding capital stock of the Company, as of the Closing Time, will be, as set forth in Schedule A annexed hereto, which Schedule A has been prepared from the books and records of the Company. The shares of issued and outstanding capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable; none of the outstanding shares of capital stock of the Company was issued in violation of the preemptive or other similar rights of any securityholder of the Company. (viii) AUTHORIZATION OF AGREEMENT. This Agreement has been duly authorized, executed and delivered by the Company and the Operating Partnership. 5

(ix) AUTHORIZATION AND DESCRIPTION OF SECURITIES. The Securities to be purchased by the Underwriter from the Company have been duly authorized for issuance and sale to the Underwriter pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein will be, as of the Closing Time, validly issued, fully paid and non-assessable; the Common Stock conforms, in all material respects, to all statements relating thereto contained in the Prospectus or in documents incorporated therein by reference and such description conforms, in all material respects, to the rights set forth in the instruments defining the same; no holder of the Securities will be subject to personal liability by reason of being such a holder; and the issuance of the Securities is not subject to the preemptive or other similar rights of any securityholder of the Company; the Company has duly reserved a sufficient number of shares of Common Stock for issuance upon exchange of outstanding units of limited partnership of the Operating Partnership ("OP Units") in accordance with the Second Amended and Restated Limited Partnership Agreement of the Operating Partnership as amended to date ("Operating Partnership Agreement"). (x) AUTHORIZATION AND DESCRIPTION OF OP UNITS. The issued and outstanding OP Units have been duly authorized and validly issued and are fully paid. OP Units issued and sold in connection with the acquisition of properties currently under contract to be acquired have been and will be offered, issued and sold in compliance with all applicable laws (including, without limitation, federal and state securities laws). (xi) ABSENCE OF DEFAULTS AND CONFLICTS. Neither the Company nor any of its Subsidiaries is in violation of its charter or by-laws or in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or other agreement or instrument to which the Company or any of its Subsidiaries is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any Subsidiary is subject (collectively, "Agreements and Instruments") except for such defaults that would not result in a Material Adverse Effect; and the execution, delivery and performance of this Agreement and the consummation of the transactions contemplated in this Agreement and the Registration Statement (including the issuance and sale of the Securities and the use of the proceeds from the sale of the Securities as described in the Prospectus under the caption "Use of Proceeds") and compliance by the Company and the Operating Partnership with 6

their obligations under this Agreement have been duly authorized by all necessary corporate or partnership action, as the case may be, and (except as contemplated by the Prospectus) do not and will not, whether with or without the giving of notice or passage of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any of the Properties (as defined in the Registration Statement) or any other property or assets of the Company or any Subsidiary pursuant to, the Agreements and Instruments or violations of any applicable law, statute, rule, regulation, judgment, order, writ or decree of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company or any Subsidiary or any of their assets, properties or operations (except for such conflicts, breaches or defaults or liens, charges, encumbrances or violations that would not result in a Material Adverse Effect), nor will such action result in any violation of the provisions of the charter or by-laws of the Company or any Subsidiary. As used herein, the term "Repayment Event" means any event or condition which gives the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder's behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company or any Subsidiary. (xii) ABSENCE OF LABOR DISPUTE. No material labor dispute with the employees of the Company or any Subsidiary exists or, to the knowledge of the Company, is imminent. (xiii) ABSENCE OF PROCEEDINGS. There is no action, suit, proceeding, inquiry or investigation before or brought by any court or governmental agency or body, domestic or foreign, now pending, or, to the knowledge of the Company, threatened, against or affecting the Company or any Subsidiary, which is required to be disclosed in the Registration Statement (other than as disclosed therein), or which might reasonably be expected to result in a Material Adverse Effect, or which might reasonably be expected to materially and adversely affect the Properties or assets thereof or the consummation of the transactions contemplated in this Agreement or the performance by the parties of their obligations hereunder; the aggregate of all pending legal or governmen tal proceedings to which the Company or any Subsidiary is a party or of which any of their respective property or assets, including without limitation the Properties, is the subject which are not described in the Registration Statement, including ordinary routine litigation incidental to the business, could not reasonably be expected to result in a Material Adverse Effect. 7

(xiv) QUALIFICATION AS A REIT. Commencing with the taxable year ended December 31, 1997, the Company is organized in conformity with the requirements for qualification as a real estate investment trust (a "REIT") under the Internal Revenue Code of 1986, as amended (the "Code"), and its method of operation enables it to meet the requirements for taxation as a REIT under the Code. (xv) ACCURACY OF EXHIBITS. There are no contracts or documents which are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits thereto or to documents incorporated by reference therein which have not been so described and filed as required. (xvi) NEW YORK STOCK EXCHANGE LISTING. The Company's Common Stock is listed on the New York Stock Exchange ("NYSE"). Application has been made to list the Securities on the NYSE, and as of the Closing Time the Securities shall have been approved for listing on the NYSE, subject to official notice of issuance. (xvii) ABSENCE OF FURTHER REQUIREMENTS. No filing with, or authoriza tion, approval, consent, license, order, registration, qualification or decree of, any court or governmental authority or agency is necessary or required for the performance by the Company and the Operating Partnership of their obligations hereunder, in connection with the offering, issuance or sale of the Securities under this Agreement or the consummation of the transactions contemplated by this Agreement, except such as have been already obtained or as may be required under the 1933 Act or the 1933 Act Regulations and foreign or state securities or blue sky laws. (xviii) POSSESSION OF LICENSES AND PERMITS. The Company and its Subsidiaries possess such permits, licenses, approvals, consents and other authorizations (collectively, "Governmental Licenses") issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the business now operated by them; the Company and its Subsidiaries are in compliance with the terms and conditions of all such Governmental Licenses, except where the failure so to comply would not, singly or in the aggregate, have a Material Adverse Effect; all of the Governmental Licenses are valid and in full force and effect, except when the invalidity of such Governmental Licenses or the failure of such Governmental Licenses to be in full force and effect would not have a Material Adverse Effect; and neither the Company nor any of its Subsidiaries has received any notice of proceedings relating to the revocation or 8

modification of any such Governmental Licenses which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Effect. (xix) THE PROPERTIES. (a) The Operating Partnership and the Subsidiar ies have good and marketable title in fee simple to all of the Properties and good and marketable title to all other real properties owned by them, in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind except such as (i) are described in the Prospectus or in documents incorporated by reference therein or (ii) do not, singly or in the aggregate, materially affect the value of such property and do not interfere with the use made and proposed to be made of such property by the Company or any of its Subsidiaries; (b) all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances on or affecting the properties and assets of the Company or any of the Subsidiaries that are required to be disclosed in the Prospectus are disclosed therein or in documents incorporated by reference therein; (c) neither the Company nor the Operating Partnership knows of any violation of any municipal, state or federal law, rule or regulation (including those pertaining to environmental matters) concerning the Properties or any part thereof which would have a Material Adverse Effect; (d) each of the Properties complies with all applicable zoning laws, ordinances, regulations and deed restrictions or other covenants in all material respects and, if and to the extent there is a failure to comply, such failure does not result in a Material Adverse Effect and will not result in a forfeiture or reversion of title; (e) none of the Company nor any Subsidiary has received from any governmental authority any written notice of any condemnation of or zoning change affecting the Properties or any part thereof, and none of the Company nor any Subsidiary knows of any such condemnation or zoning change which is threatened and which if consummated would have a Material Adverse Effect; and (f) no lessee of any portion of any of the Properties is in default under any of the leases governing such Properties and there is no event which, but for the passage of time or the giving of notice or both, would constitute a default under any of such leases, except such defaults that would not have a Material Adverse Effect. (xx) INSURANCE. The Company and each of the Subsidiaries is insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which they will be engaged; and neither the Company nor any of the Subsidiaries has any reason to believe that any of them will not be able to renew its existing 9

insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business. (xxi) TAXES. The Company and each of the Subsidiaries has filed all material foreign, federal, state and local tax returns that are required to be filed or have requested extensions thereof (except in any case in which the failure so to file would not have a Material Adverse Effect) and has paid all taxes required to be paid by it and any other assessment, fine or penalty levied against it, to the extent that any of the foregoing is due and payable, except for any such assessment, fine or penalty that is currently being contested in good faith or as described in or contemplated by the Prospectus. (xxii) MORTGAGES AND DEEDS OF TRUST. Except as set forth in the Registration Statement and the Prospectus, the mortgages and deeds of trust encumbering the properties and assets described in the Prospectus are not convertible and neither the Company, any of its Subsidiaries, nor any person affiliated therewith holds a participating interest therein, and such mortgages and deeds of trust are not cross-defaulted or cross-collateralized to any property not owned directly or indirectly by the Company or any of its Subsidiaries. (xxiii) COMPLIANCE WITH CUBA ACT. The Company has complied with, and is and will be in compliance with, the provisions of that certain Florida act relating to disclosure of doing business with Cuba, codified as Section 517.075 of the Florida statutes, and the rules and regulations thereunder (collectively, the "Cuba Act") or is exempt therefrom. (xxiv) INVESTMENT COMPANY ACT. The Company and the Operating Partnership are not, and upon the issuance and sale of the Securities as herein contemplated and the application of the net proceeds therefrom as described in the Prospectus will not be, an "investment company" as such term is defined in the Investment Company Act of 1940, as amended (the "1940 Act"). (xxv) ENVIRONMENTAL LAWS. Except as otherwise disclosed in the Prospectus or in the Phase I Environmental Site Assessments and Asbestos Survey Reports previously delivered to the Underwriter or its counsel (the "Environmental Reports"), or except as would not, singly or in the aggregate, have a Material Adverse Effect, (i) to the best knowledge of the Company, the Company and its Subsidiaries have been and are in compliance with applicable Environmental Statutes; (ii) to the best knowledge of the Company, neither the Company, any of the Subsidiaries, nor any other owners of the property at any 10

time or any other party has at any time released (as such term is defined in Section 101(22) of CERCLA (as hereinafter defined)) or otherwise disposed of Hazardous Materials (as hereinafter defined) on, to or from the Properties; (iii) the Company does not intend to use the Properties or any subsequently acquired properties, other than in compliance with applicable Environmental Statutes (as hereinafter defined); (iv) neither the Company nor any of the Subsidiaries knows of any seepage, leak, discharge, release, emission, spill, or dumping of Hazardous Materials into waters (including, but not limited, to groundwater and surface water) on, beneath or adjacent to the Properties or onto lands from which Hazardous Materials might seep, flow or drain into such waters; (v) neither the Company nor any of the Subsidiaries has received any notice of, or has any knowledge of any occurrence or circumstance which, with notice or passage of time or both, would give rise to a claim under or pursuant to any Environmental Statute with respect to the Properties or the assets described in the Prospectus or arising out of the conduct of the Company or its Subsidiaries; (vi) neither the Properties nor any other land owned by the Company or any of the Subsidiaries is included or, to the best of the Company's knowledge, proposed for inclusion on the National Priorities List issued pursuant to CERCLA by the United States Environmental Protection Agency (the "EPA") or to the best of the Company's knowledge, proposed for inclusion on any similar list or inventory issued pursuant to any other Environmental Statute or issued by any other Governmental Authority (as hereinafter defined). As used herein, "Hazardous Material" shall include, without limitation any flammable explosives, radioactive materials, hazardous materials, hazardous wastes, toxic substances, or related materials, asbestos or any hazardous material as defined by any federal, state or local environmental law, ordinance, rule or regulation including, without limitation, the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended, 42 U.S.C. ss.ss. 9601-9675 ("CERCLA"), the Hazardous Materials Transportation Act, as amended, 49 U.S.C. ss.ss. 1801-1819, the Resource Conservation and Recovery Act, as amended, 42 U.S.C. ss.ss. 6901-K, the Emergency Planning and Community Right-to-Know Act of 1986, 42 U.S.C. ss.ss. 11001-11050, the Toxic Substances Control Act, 15 U.S.C. ss.ss. 2601-2671, the Federal Insecticide, Fungicide and Rodenticide Act, 7 U.S.C. ss.ss. 136-136y, the Clean Air Act, 42 U.S.C. ss.ss. 7401-7642, the Clean Water Act (Federal Water Pollution Control Act), 33 U.S.C. ss.ss. 1251-1387, the Safe Drinking Water Act, 42 U.S.C. ss.ss. 300f- 300j-26, and the Occupational Safety and Health Act, 29 U.S.C. ss.ss. 651-678, as any of the above statutes may be amended from time to time, and in the regulations promulgated pursuant to each of the foregoing (including environ- 11

mental statues not specifically defined herein) (individually, an "Environmental Statute" and collectively "Environmental Statutes") or by any federal, state or local governmental authority having or claiming jurisdiction over the properties and assets described in the Prospectus (a "Governmental Authority"). (xxvi) REGISTRATION RIGHTS. Except as described in the Registration Statement, there are no registration rights or other similar rights to have any securities registered pursuant to the Registration Statement. Except as described in the Registration Statement or as otherwise disclosed to the Underwriter by the Company in a writing identified to this Agreement, there are no registration rights or other similar rights to have any securities otherwise registered by the Company under the 1933 Act. (b) OFFICER'S CERTIFICATES. Any certificate signed by any officer of the Company or any of its subsidiaries delivered to the Underwriter or to counsel for the Underwriter shall be deemed a representation and warranty solely by the Company to the Underwriter as to the matters covered thereby. SECTION 2. SALE AND DELIVERY TO UNDERWRITER; CLOSING. (a) SALE OF SECURITIES. On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company agrees to sell to the Underwriter, and the Underwriter agrees to purchase from the Company, at a price of $35.294375 per share, an aggregate of 4,000,000 shares of Common Stock, for an aggregate purchase price of $141,177,500. (b) PAYMENT. Payment of the purchase price for, and delivery of certificates for, the Securities shall be made at the offices of Skadden, Arps, Slate, Meagher & Flom LLP, 919 Third Avenue, New York, New York, or at such other place as shall be agreed upon by the Underwriter and the Company, at 9:00 A.M. (Eastern time) on May 25, 1999, or such other time not later than ten business days after such date as shall be agreed upon by the Underwriter and the Company (such time and date of payment and delivery being herein called "Closing Time"). Payment shall be made to the Company by wire transfer of immediately available funds to a bank account designated by the Company, against delivery to the Underwriter of certificates for the Securities to be purchased by them. (c) DENOMINATIONS; REGISTRATION. Certificates for the Securities shall be in such denominations and registered in such names as the Underwriter may request in 12

writing at least two full business days before the Closing Time. The certificates for the Securities will be made available for examination and packaging by the Underwriter in The City of New York not later than 10:00 A.M. (Eastern time) on the business day prior to the Closing Time. SECTION 3. COVENANTS OF THE COMPANY. Each of the Company and the Operating Partnership covenants with the 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 430A or Rule 434, as applicable, and will notify the Underwriter promptly, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement shall become effective, or any supplement to the Prospectus or any amended Prospectus shall have been filed, (ii) of the receipt of any comments from the Commission, (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for additional information, and (iv) of 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 any preliminary 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(b) and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort 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. The Company will give the Underwriter notice of its intention to file or prepare any amendment to the Registration Statement (including any filing under Rule 462(b)), any Term Sheet or any amendment, supplement or revision to either the prospectus included in the Registration Statement at the time it became effective or to the Prospectus, will furnish the Underwriter with copies of any such documents a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file or use any such document to which the Underwriter or counsel for the Underwriter shall reasonably object. (c) DELIVERY OF REGISTRATION STATEMENTS. The Company has furnished or, upon request, will deliver to the Underwriter and counsel for the Underwriter, without charge, signed copies of the Registration Statement as originally filed and of each 13

amendment thereto (including exhibits filed therewith or incorporated by reference therein) and signed copies of all consents and certificates of experts, and will also deliver to the Underwriter, without charge, a conformed copy of the Registration Statement as originally filed and of each amendment thereto (without exhibits). The copies of the Registration Statement and each amendment thereto furnished to the Underwriter will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted or required by Regulation S-T. (d) DELIVERY OF PROSPECTUS. The Company will furnish to the Underwriter, without charge, during the period when the Prospectus is required to be delivered under the 1933 Act or the 1934 Act, such number of copies of the Prospectus (as amended or supplemented) as the Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to the Underwriter will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted or required by Regulation S-T. (e) CONTINUED COMPLIANCE WITH SECURITIES LAWS. The Company will comply with the 1933 Act and the 1933 Act Regulations so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Prospectus. If at any time when a prospectus is required by the 1933 Act to be delivered in connection with sales of the Securities, any event shall occur or condition shall exist as a result of which it is necessary, in the reasonable opinion of counsel for the Underwriter or for the Company, to amend the Registration Statement or amend or supplement the Prospectus in order that the Prospectus will not include any untrue statements of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in the light of the circumstances existing at the time it is delivered to a purchaser, or if it shall be necessary, in the reasonable opinion of such counsel, at any such time to amend the Registration Statement or amend or supplement the Prospectus in order to comply with the requirements of the 1933 Act or the 1933 Act Regulations, the Company will promptly prepare and file with the Commission, subject to Section 3(b), such amendment or supplement as may be necessary to correct such statement or omission or to make the Registration Statement or the Prospectus comply with such requirements, and the Company will furnish to the Underwriter such number of copies of such amendment or supplement as the Underwriter may reasonably request. (f) BLUE SKY QUALIFICATIONS. The Company will use its best efforts, in cooperation with the Underwriter, to qualify, if necessary, the Securities for offering and sale under the applicable securities laws of such states and other jurisdictions (domestic or foreign) as the Underwriter may designate and to maintain such qualifications in 14

effect for a period of not more than one year from the later of the effective date of the Registration Statement; provided, however, that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject. In each jurisdiction in which the Securities have been so qualified, the Company will file such statements and reports as may be required by the laws of such jurisdiction to continue such qualification in effect for a period of not more than one year from the effective date of the Registration Statement. (g) RULE 158. The Company will timely file such reports pursuant to the 1934 Act as are necessary in order to make generally available to its securityholders as soon as practicable an earnings statement for the purposes of, and to provide the benefits contemplated by, the last paragraph of Section 11(a) of the 1933 Act. (h) USE OF PROCEEDS. The Company will use the net proceeds received by it from the sale of the Securities in the manner specified in the Prospectus under "Use of Proceeds". (i) LISTING. The Company will use its best efforts to effect the listing of the Securities on the New York Stock Exchange. (j) RESTRICTION ON SALE OF SECURITIES. During a period of 90 days from May 20, 1999, the Company and the Operating Partnership will not, without the prior written consent of the Underwriter, (i) directly or indirectly, offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of any share of Common Stock or OP Units or any securities convertible into or exercisable or exchangeable for Common Stock or OP Units, or file any registration statement under the 1933 Act with respect to any of the foregoing or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Common Stock, whether any such swap or transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (A) the Securities to be sold hereunder, (B) any shares of Common Stock issued or options to purchase Common Stock granted under the current employee benefit plans of the Company referred to in the Prospectus, or any employee benefit plans of the Company which have been approved by the requisite vote of the stockholders of the Company at a duly called meeting of stockholders or any employee benefit plans of the Company in which all non-officer full-time employees of the Company are eligible to 15

participate on substantially similar terms, (C) the issuance by the Company of shares of Common Stock in exchange for outstanding partnership units of the Operating Partnership in accordance with terms of the partnership agreement of the Operating Partnership or (D) the issuance of shares of capital stock of the Company or partnership units of the Operating Partnership in connection with the acquisition of properties in the ordinary course of business. (k) QUALIFICATION AS A REIT. The Company will use its best efforts to meet the requirements to qualify, commencing with the taxable year ended December 31, 1997, as a REIT under the Code, subject to the fiduciary duties of the Board of Directors of the Company to manage the business of the Company in the best interest of its stockholders. SECTION 4. PAYMENT OF EXPENSES. (a) EXPENSES. The Company will pay all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and of each amendment thereto, (ii) the printing and delivery to the Underwriter of this Agreement, any Agreement among Underwriters and such other documents as may be required in connection with the offering, purchase, sale, issuance or delivery of the Securities, (iii) the preparation, issuance and delivery of the certificates for the Securities to the Underwriter, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Securities to the Underwriter, (iv) the fees and disbursements of the Company's counsel, accountants and other advisors, (v) the qualification or registration (or exemption therefrom) of the Securities under securities laws in accordance with the provisions of Section 3(f) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriter in connection therewith and in connection with the preparation of the Blue Sky Survey and any supplement thereto, (vi) the printing and delivery to the Underwriter of copies of each preliminary prospectus, any Term Sheets and of the Prospectus and any amendments or supplements thereto, (vii) the preparation, printing and delivery to the Underwriter of copies of the Blue Sky Survey and any supplement thereto, (viii) the fees and expenses of any transfer agent or registrar for the Securities, (ix) the filing fees incident to, and the reasonable fees and disbursements of counsel to the Underwriter in connection with, the review by the NASD of the terms of the sale of the Securities, and (x) the fees and expenses incurred in connection with the listing of the Securities on the New York Stock Exchange. (b) TERMINATION OF AGREEMENT. If this Agreement is terminated by the Underwriter in accordance with the provisions of Section 5 or Section 9(a)(i) hereof, the 16

Company shall reimburse the Underwriter for all of its out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriter, unless such termination was pursuant to the condition set forth in Section 5(i) and the failure to satisfy such condition was solely attributable to the Underwriter. SECTION 5. CONDITIONS OF UNDERWRITER'S OBLIGATIONS. The obligations of the Underwriter hereunder are subject to the accuracy of the representations and warranties of the Company contained in Section 1 hereof or in certificates of any officer of the Company or any subsidiary of the Company delivered pursuant to the provisions hereof, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions: (a) EFFECTIVENESS OF REGISTRATION STATEMENT; FILING OF PROSPECTUS SUPPLE MENT. The Registration Statement has become effective and at the Closing Time no stop order suspending the effectiveness of the Registration Statement shall have been issued under the 1933 Act or proceedings therefor initiated or threatened by the Commission, and any request on the part of the Commission for additional information shall have been complied with to the reasonable satisfaction of counsel to the Underwriter. The Prospectus, as supplemented by the prospectus supplement relating to the offering of the Securities, shall have been filed with the Commission pursuant to Rule 424(b) within the applicable time period prescribed for such filing by the regulations promulgated under the 1933 Act and in accordance with Section 3(a) hereof. (b) OPINION OF COUNSEL FOR COMPANY. At Closing Time, the Underwriter shall have received the favorable opinion, dated as of Closing Time, of Goodwin, Procter & Hoar LLP, counsel for the Company and the Operating Partnership, in form and substance satisfactory to counsel for the Underwriter, to the effect set forth in Exhibit A hereto with such qualifications and explanatory notes thereto as counsel to the Underwriter may reasonably accept. (c) OPINION OF GENERAL COUNSEL OF COMPANY. At Closing Time, the Underwriter shall have received the favorable opinion, dated as of Closing Time, of Frederick J. DeAngelis, General Counsel of the Company, in form and substance satisfactory to counsel for the Underwriter, to the effect set forth in Exhibit B hereto with such qualifications and explanatory notes thereto as counsel to the Underwriter may reasonably accept. (d) OPINION OF COUNSEL FOR UNDERWRITER. At Closing Time, the Underwriter shall have received the favorable opinion, dated as of Closing Time, of Skadden, Arps, Slate, Meagher & Flom LLP, counsel for the Underwriter, with respect to the matters 17

set forth in clauses (i), (ix), (x), (solely as to preemptive or other similar rights arising by operation of law or under the charter or by-laws of the Company), (xii) through (xiv), inclusive, and the penultimate paragraph of Exhibit A hereto; PROVIDED, that such counsel's opinion may state that such counsel is expressing no opinion or belief as to the compliance as to form of the documents incorporated by reference into the Registration Statement and Prospectus pursuant to Item 12 of Form S-3. In giving the opinions described in paragraphs (b), (c) and (d) above, each counsel may rely, as to all matters governed by the laws of jurisdictions other than the law of the Commonwealth of Massachusetts, the federal law of the United States and the General Corporation Law and the Revised Uniform Limited Partnership Act of the State of Delaware, upon the opinions of counsel satisfactory to the Underwriter. Such counsel may also state that, insofar as such opinion involves factual matters, they have relied, to the extent they deem proper, upon certificates of officers of the Company and its Subsidiaries and certificates of public officials. (e) OFFICERS' CERTIFICATE. At Closing Time, there shall not have been, since the date hereof or since the respective dates as of which information is given in the Prospectus, except as contemplated by the Prospectus, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company, the Operating Partnership and the Subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, and the Underwriter shall have received a certificate of the President or a Vice President of the Company and of the chief financial or chief accounting officer of the Company and appropriate officers of the Company, as General Partner, on behalf of the Operating Partnership, dated as of Closing Time, to the effect that (i) there has been no such material adverse change, (ii) the representations and warranties in Section 1(a) hereof are true and correct in all material respects with the same force and effect as though expressly made at and as of Closing Time, (iii) the information incorporated by reference into the Prospectus consisting of Exhibit 99.1 to the Company's Form 8-K Current Report dated April 27, 1999 is accurate in all material respects, (iv) the Company has complied in all material respects with all agreements and satisfied all conditions on its part to be performed or satisfied at or prior to Closing Time, and (v) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or are pending or are contemplated by the Commission. (f) ACCOUNTANT'S COMFORT LETTER. At the time of the execution of this Agreement, the Underwriter shall have received from PriceWaterhouseCoopers LLP a letter dated such date, in form and substance satisfactory to the Underwriter, containing 18

statements and information of the type ordinarily included in accountants' "comfort letters" to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus. (g) BRING-DOWN COMFORT LETTER. At Closing Time, the Underwriter shall have received from PriceWaterhouseCoopers LLP a letter, dated as of Closing Time, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (f) of this Section, except that the specified date referred to shall be a date not more than three business days prior to Closing Time. (h) APPROVAL OF LISTING. At Closing Time, the Securities shall have been approved for listing on the New York Stock Exchange, subject only to official notice of issuance. (i) NO OBJECTION. The NASD shall have confirmed that it has not raised any objection with respect to the fairness and reasonableness of the underwriting terms and arrangements. (j) LOCK-UP AGREEMENTS. Messrs. Mortimer Zuckerman, Chairman, and Edward H. Linde, President and Chief Executive Officer, shall have executed and delivered to the Underwriter lock-up agreements containing substantially the same terms and conditions as are set forth in the first sentence of Section 3(j) hereof; such agreements shall not have been amended or revoked; and such agreements shall be in full force and effect. (k) ADDITIONAL DOCUMENTS. At Closing Time, counsel for the Underwriter shall have been furnished with such documents and opinions as they may reasonably require for the purpose of enabling them to pass upon the issuance and sale of the Securities as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Securities as herein contemplated shall be reasonably satisfactory in form and substance to the Underwriter and counsel for the Underwriter. (l) TERMINATION OF AGREEMENT. If any condition specified in this Section shall not have been fulfilled when and as required to be fulfilled, this Agreement may be terminated by the Underwriter by notice to the Company at any time at or prior to Closing Time, and such termination shall be without liability of any party to any other party except as provided in Section 4 and except that Sections 1, 6, 7 and 8 shall survive any such termination and remain in full force and effect. 19

SECTION 6. INDEMNIFICATION. (a) INDEMNIFICATION OF UNDERWRITER. The Company and the Operating Partnership jointly agree to indemnify and hold harmless the Underwriter and each person, if any, who controls the Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows: (i) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including the Rule 430A Information and the Rule 434 Information, if applicable, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact included in any preliminary prospectus or the Prospectus (or any amendment or supplement thereto), or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; (ii) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company; and (iii) against any and all expense whatsoever, as incurred (including the fees and disbursements of counsel chosen by the Underwriter), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under (i) or (ii) above; PROVIDED, HOWEVER, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Company and the Operating Partnership by the 20

Underwriter expressly for use in the Registration Statement (or any amendment thereto), or any preliminary prospectus or the Prospectus (or any amendment or supplement thereto). (b) INDEMNIFICATION OF COMPANY, DIRECTORS AND OFFICERS. The Underwriter agrees to indemnify and hold harmless the Company, its directors, each of its officers who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act against any and all loss, liability, claim, damage and expense described in the indemnity contained in subsection (a) of this Section, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), or any preliminary prospectus or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information furnished to the Company by the Underwriter expressly for use in the Registration Statement (or any amendment thereto) or such preliminary prospectus or the Prospectus (or any amendment or supplement thereto). The Company and the Operating Partnership acknowledge that the statements set forth in the last paragraph of the cover page and in the fifth and sixth paragraphs under the caption "Underwriting" in the Prospectus constitute the only information furnished in writing by or on behalf of the Underwriter expressly for use in the Registration Statement relating to the Securities as originally filed or in any amendment thereof, related preliminary prospectus or the Prospectus or in any amendment thereof or supplement thereto, as the case may be. (c) ACTIONS AGAINST PARTIES; NOTIFICATION. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) above, counsel to the indemnified parties shall be selected by the Underwriter, and, in the case of parties indemnified pursuant to Section 6(b) above, counsel to the indemnified parties shall be selected by the Company. An indemnifying party may participate at its own expense in the defense of any such action; provided, however, that counsel to the indemnifying party shall not (except with the consent of the indemnified party) also be counsel to the indemnified party. Notwithstanding the foregoing, if it so elects within a reasonable time after receipt of such notice, an indemnifying party, jointly with any other indemnifying parties receiving such notice, may assume the defense of such action with counsel chosen by it and approved by the 21

indemnified parties defendant in such action (which approval shall not be unreasonably withheld), unless such indemnified parties reasonably object to such assumption on the ground that there may be legal defenses available to them which are different from or in addition to those available to such indemnifying party. If an indemnifying party assumes the defense of such action, the indemnifying party shall not be liable for any fees and expenses of counsel for the indemnified parties incurred thereafter in connection with such action, except that the indemnifying party shall be liable for the reasonable costs of investigation subsequently incurred by the indemnified party in connection with the defense. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, which consent shall not be unreasonably withheld, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party. (d) SETTLEMENT WITHOUT CONSENT IF FAILURE TO REIMBURSE. If at any time an indemnified party shall have requested in writing an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement; PROVIDED, HOWEVER, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, an indemnifying party shall not be liable for any settlement of the nature contemplated by this Section 6(d) effected without its written consent if (x) such indemnifying party reimburses such indemnified party in accordance with such request to the extent it considers such request to be reasonable; and (y) such indemnifying party 22

provides written notice to the indemnified party substantiating the unpaid balance as unreasonable, in each case prior to the date of such settlement. SECTION 7. CONTRIBUTION. If the indemnification provided for in Section 6 hereof is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Operating Partnership on the one hand and the Underwriter on the other hand from the offering of the Securities pursuant to this Agreement or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company and the Operating Partnership on the one hand and of the Underwriter on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Operating Partnership on the one hand and the Underwriter on the other hand in connection with the offering of the Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company and the total underwriting discount received by the Underwriter, in each case as set forth on the cover of the Prospectus, bear to the aggregate initial public offering price of the Securities as set forth on such cover. The relative fault of the Company and the Operating Partnership on the one hand and the Underwriter on the other hand shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company, the Operating Partnership or by the Underwriter and the parties' relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company, the Operating Partnership and the Underwriter agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and 23

referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission. Notwithstanding the provisions of this Section 7, the Underwriter shall not be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which the Underwriter has otherwise been required to pay by reason of any such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the 1933 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. For purposes of this Section 7, each person, if any, who controls the Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company. SECTION 8. REPRESENTATIONS, WARRANTIES AND AGREEMENTS TO SURVIVE DELIVERY. All representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company, the Operating Partnership or any of the Subsidiaries submitted pursuant hereto, shall remain operative and in full force and effect, regardless of any investigation made by or on behalf of the Underwriter or controlling person, or by or on behalf of the Company, and shall survive delivery of the Securities to the Underwriter. SECTION 9. TERMINATION OF AGREEMENT. (a) TERMINATION; GENERAL. The Underwriter may terminate this Agreement, by notice to the Company, at any time at or prior to Closing Time (i) if there has been, since the time of execution of this Agreement or since the respective dates as of which information is given in the Prospectus, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the 24

Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, or (ii) if there has occurred any material adverse change in the financial markets in the United States or the international financial markets, any outbreak of hostilities or escalation thereof or other calamity or crisis or any change or development involving a prospective change in national or international political, financial or economic conditions, in each case the effect of which is such as to make it, in the judgment of the Underwriter, impracticable to market the Securities or to enforce contracts for the sale of the Securities, or (iii) if trading in any securities of the Company has been suspended or materially limited by the Commission or the New York Stock Exchange, or if trading generally on the American Stock Exchange or the New York Stock Exchange or in the Nasdaq National Market has been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required, by any of said exchanges or by such system or by order of the Commission, the NASD or any other governmental authority, or (iv) if a banking moratorium has been declared by either Federal or New York authorities. (b) LIABILITIES. If this Agreement is terminated pursuant to this Section, such termination shall be without liability of any party to any other party except as provided in Section 4 hereof, and provided further that Sections 1, 6, 7 and 8 shall survive such termination and remain in full force and effect. SECTION 10. NOTICES. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriter shall be directed to Goldman, Sachs & Co., 85 Broad Street, New York, New York 10004, attention of Registration Department; and notices to the Company and the Operating Partnership shall be directed to it at 8 Arlington Street, Boston, Massachusetts 02116, attention of Frederick J. DeAngelis, Esq. Notices given by telex or telephone shall be confirmed in writing. SECTION 11. PARTIES. This Agreement shall each inure to the benefit of and be binding upon the Underwriter and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Underwriter and the Company and their respective successors and the controlling persons and officers and directors referred to in Sections 6 and 7 and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Underwriter and the Company and their respective successors, and said controlling persons and officers and directors and their 25

heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Securities from the Underwriter shall be deemed to be a successor by reason merely of such purchase. SECTION 12. GOVERNING LAW AND TIME. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK. SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME. SECTION 13. EFFECT OF HEADINGS. The Article and Section headings herein and the Table of Contents are for convenience only and shall not affect the construction hereof. 26

If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument, along with all counterparts, will become a binding agreement between the Underwriter and the Company in accordance with its terms. Very truly yours, BOSTON PROPERTIES, INC. By /s/ David G. Gaw ------------------------------------- Name: David G. Gaw Title: Chief Financial Officer and Senior Vice President BOSTON PROPERTIES LIMITED PARTNERSHIP By: Boston Properties, Inc., its general partner By /s/ David G. Gaw ------------------------------------- Name: David G. Gaw Title: Chief Financial Officer and Senior Vice President CONFIRMED AND ACCEPTED, as of the date first above written: GOLDMAN, SACHS & CO. By: /s/ Goldman, Sachs & Co. ---------------------------

SCHEDULE A CAPITALIZATION OF THE COMPANY The total number of shares of all classes of capital stock which the Company has the authority to issue is 450,000,000 shares, consisting of (a) 250,000,000 shares of common stock, par value $.01 per share, (b) 150,000,000 shares of excess stock, par value $.01 per share, and (c) 50,000,000 shares of preferred stock, par value $.01 per share. As of May 19, 1999, the Company had outstanding: (i) 63,548,144 shares of common stock; and (ii) 2,000,000 shares of Series A Convertible Redeemable Preferred Stock. Sch A-1

SCHEDULE B Certain Properties 599 Lexington Avenue One Independence Square Two Independence Square Democracy Center Capital Gallery 2300 N Street Long Wharf Marriott Cambridge Center Marriott 280 Park Avenue 100 East Pratt Street 875 Third Avenue Riverfront Plaza The Mulligan/Griffin Portfolio A-1


EXHIBIT 5 [LETTERHEAD] May 25, 1999 Boston Properties, Inc. 800 Boylston Street Boston, Massachusetts 02199 Ladies and Gentlemen: We have acted as counsel to Boston Properties, Inc., a Delaware corporation (the "Company"), in connection with the offer and sale by the Company of 4,000,000 shares (the "Shares") of common stock, par value $.01 per share, of the Company. This opinion is being delivered in connection with (i) the Company's Registration Statement on Form S-3 (No. 333-69375) (the "Registration Statement") relating to the registration of the offering and sale under the Securities Act of 1933, as amended, of up to $1,500,000,000 of securities of the Company, and (ii) a prospectus supplement dated May 20, 1999 (the "Prospectus Supplement") which supplements the prospectus included in such Registration Statement, relating to the offering of the Shares by the Company. The Shares will be offered by Goldman, Sachs & Co. (the "Underwriter") pursuant to that certain Underwriting Agreement, dated as of May 20, 1999, among the Company, Boston Properties Limited Partnership and the Underwriter (the "Underwriting Agreement"). As the basis for the opinion hereinafter expressed, we have examined such statutes, regulations, corporate records and documents, certificates of public officials and other instruments as we have deemed necessary or advisable for the purposes of this opinion. In such examination, we have assumed the authenticity of all documents submitted to us as originals and the conformity with the original documents of all documents submitted to us as copies. Based on the foregoing and on such legal considerations as we deem relevant, we are of the opinion that the Shares sold or to be sold by the Company to the Underwriter as described in the Registration Statement and the Prospectus Supplement have been duly authorized and have been, or upon delivery of such Shares and payment therefor in accordance with the Underwriting Agreement will be, validly issued, fully paid and non-assessable. We hereby consent to the use of this opinion as an exhibit to the Company's Current Report on Form 8-K dated May 25, 1999. Very truly yours, /s/ Goodwin, Procter & Hoar LLP GOODWIN, PROCTER & HOAR LLP