W I T N E S S E T H

WHEREAS, the Seller and the Purchaser executed a Purchase and Sale Agreement dated as of May 5, 2008 (the “Purchase Agreement”), with respect to the Property (this and other capitalized terms used and not otherwise defined herein shall have the meanings given such terms in the Purchase Agreement) described in Exhibit A hereto; and

WHEREAS, the Seller and the Purchaser now wish to amend the Purchase Agreement subject to and upon the terms and conditions set forth herein;

NOW, THEREFORE, for good and valuable consideration and in consideration of the mutual covenants of the parties hereto, the mutual receipt and legal sufficiency of which is hereby acknowledged, Landlord and Tenant hereby agree as follows:

1.                                      Section 1.13 is hereby deleted in its entirety and the following is inserted in substitution therefor:

1.13  “Purchase Price”  shall mean Nineteen Million Two Hundred Fifty Thousand Dollars ($19,250,000).

2.                                      As amended hereby, the Agreement is in full force and effect and is hereby ratified and confirmed.

3.                                      This Amendment may be executed in a number of identical counterparts.  If so executed, each counterpart is to be deemed an original for all purposes, and all such counterparts shall, collectively, constitute one agreement.  Such executed counterparts may be delivered by facsimile or by e-mail (in .pdf format) and any such counterparts so delivered shall be deemed original documents for all purposes.

4.                                      The Declaration of Trust of the Seller, a copy of which is duly filed with the Department of Assessments and Taxation of the State of Maryland, provides that the name “HRPT Properties Trust” refers to the trustees under such Declaration of Trust collectively as trustees, but not individually or personally, and that no trustee, officer, shareholder, employee or agent of the