EXHIBIT 3.156 AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT OF OLS OFFICE PARTNERS L.P.

                    THIS AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT of OLS Office Partners L.P. (the “Partnership”) is made and entered into as of this 14th day of April, 2005, by and between Brandywine Midatlantic LP, a Delaware limited partnership as the limited partner (“Limited Partner”), and Brandywine One Logan LLC, a Pennsylvania limited liability company, as the general partner (“General Partner” and together with the Limited Partner, the “Partners”).  This Agreement amends and restates in its entirety the Partnership’s Limited Partnership Agreement dated February 28, 1997 by and between the parties listed on Amended Schedule A thereto.  Capitalized terms are defined below.

                    NOW, THEREFORE, in consideration of the mutual promises and agreements herein made and intending to be legally bound, the Partners hereby agree as follows:

          1.1.     Formation .  The Partnership is an existing Delaware limited partnership originally formed and organized on February 19, 1997 pursuant to the provisions of the Act.

          1.2.     Name .  The name of the Partnership is OLS OFFICE PARTNERS L.P. or such other name as the General Partner from time to time may select.

          1.3.     Place of Business .  The principal place of business of the Partnership shall be at 401 Plymouth Road, Suite 500, Plymouth Meeting, PA 19462, or such other place as the General Partner may from time to time designate.  The Partnership may maintain such other offices at such other places as the General Partner deems advisable.

          1.4.     Purpose .  The Partnership is organized to pursue any lawful purpose.

          1.5.     Term .  The Partnership shall continue until the Partnership is terminated in accordance with the terms of this Agreement.

          2.1.     Additional Capital Contributions or Loans .  No Partner shall be obligated or required to make any additional capital contributions or advance any funds to the Partnership unless all of the Partners unanimously agree to do so and unanimously agree as to the amount to be so contributed.

          2.2.     Allocations and Distributions .  All allocations of profits and losses and all distributions of cash shall be made in accordance with the Partners’ Percentage Interests.  The Percentage Interest of the General Partner shall be one percent (1%), and the Percentage Interest of the Limited Partner shall be ninety nine percent (99%).  Distributions out of funds legally available therefor shall be made at such times as the General Partner determines.

          3.1.1.     Management and Control .  The General Partner shall manage and control the business and affairs of the Partnership and shall have all of the rights and powers which may be possessed by a general partner under the Act.  Except as otherwise required under the Act or as provided herein, the General Partner shall make all decisions with respect to the business and affairs of the Partnership, and the Limited Partner shall have no right to participate in the management of the Partnership.

          4.1.     Restriction .  A Partner shall not, without the consent of the other Partner, make any Transfer of all or any portion of its Interest.

          4.2.     Transfer in Violation of Agreement .  Any purported Transfer of an Interest which is not made in compliance with this Agreement shall be null and void ab initio and of no force or effect whatsoever.

          5.1.     Records .  The Partnership shall maintain at its principal place of business:  (i) true and full information regarding the status of the business and financial affairs of the Partnership; (ii) a current list of the name and last known address of each of its Partners; (iii) a copy of this Agreement and the Partnership’s Certificate of Limited Partnership and all amendments thereto; (iv) the accounting books and records and minutes of proceedings of the Partners; and (v) any other information regarding the affairs of the Partnership as the General Partner determines is just and reasonable.

          5.2.     Fiscal Year .  Unless otherwise designated by the Partners, the fiscal year of the Partnership shall end on December 31.

          5.3.     Partnership Funds .  Pending application or distribution, the funds of the Partnership shall be deposited in such bank accounts, or invested in such interest-bearing or non-interest-bearing investments, including without limitation, federally insured checking and savings accounts, certificates of deposit and time or demand-deposits in U.S. government agencies or government backed securities or such other investments as the General Partner deems appropriate and consistent with the maintenance of Brandywine Realty Trust’s qualification as a real estate investment trust under the Code.

          5.4.     Tax Returns .  The General Partner shall cause all tax returns for the Partnership to be prepared and timely filed with the appropriate authorities and shall deliver or cause to be delivered to each Partner such information as is necessary for such Partner to prepare such Partner’s federal, state and local tax returns.

          5.5.     Tax Matters Partner .  The General Partner shall be the initial Tax Matters Partner and shall represent the Partnership and the Partners before taxing authorities or courts of competent jurisdiction in tax matters affecting the Partnership and the Partners in their capacity as Partners.

          6.1.     Dissolution .  The Partnership shall be dissolved upon the earliest to occur of the following:

                              (a)       December 31, 2050;