EXHIBIT 10.5 PRUDENTIAL ASSET PURCHASE AGREEMENT

      PRUDENTIAL ASSET PURCHASE AGREEMENT

     This PRUDENTIAL ASSET PURCHASE AGREEMENT is entered into as of this 3rd day of October, 2005 among PRENTISS PROPERTIES ACQUISITION PARTNERS, L.P., a Delaware limited partnership (“Company L.P.”), PRENTISS PROPERTIES REAL ESTATE FUND I, L.P., a Delaware limited partnership ("Other Seller" and, collectively with Company L.P., "Seller") and THE PRUDENTIAL INSURANCE COMPANY OF AMERICA, a New Jersey corporation (together with its successors and assigns, “Prudential”).

     RECITALS

     Reference is made to the Agreement and Plan of Merger dated as of the date hereof by and among Brandywine Realty Trust, Brandywine Operating Partnership, L.P., Brandywine Cognac I, LLC, Brandywine Cognac II, LLC, Prentiss Properties Trust and Company L.P. (as it may be amended, the “Merger Agreement”) and the Master Agreement dated as of the date hereof between Brandywine Operating Partnership, L.P. and Prudential (the “Master Agreement”). This Agreement is referred to in the Merger Agreement as the “Prudential Asset Purchase Agreement” and is being delivered in connection with the Merger Agreement and the Master Agreement, in each case subject to the terms and conditions hereof.

     In consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which are hereby mutually acknowledged, the parties hereto hereby agree as follows:

     Section 1.      Capitalized Terms .     Capitalized terms used in this Agreement without definition shall have the respective meaning given them in the Merger Agreement.

     Section 2.      Effectiveness of this Agreement .     Notwithstanding anything to the contrary, including, without limitation, the execution and delivery of this Agreement as of the date hereof, this Agreement shall not become effective unless and until the following conditions (the “Effectiveness Conditions”) are satisfied: (i) the Final Condition Satisfaction Date occurs, and (ii) each of Company L.P. and Brandywine Operating Partnership, L.P. delivers to Prudential a certification, in form and substance reasonably satisfactory to Prudential, that confirms that all conditions to such party’s and its affiliates’ obligations to effect the REIT Merger and the OP Merger have been irrevocably satisfied or waived in writing. Upon the occurrence of the Effectiveness Conditions, this Agreement shall become fully effective as if executed and delivered as of such date.

     Section 3.      Capitalized Terms .     Listed on Exhibit A hereto are certain properties (collectively, the “Fee Owned Properties”), which are owned by the entities listed on Exhibit A as the owners thereof (each, a “Property Owner”). Listed on Exhibit B hereto is a property commonly known as High Bluff Ridge located in Del Mar, California (the “Joint Venture Owned Property”) owned by the entity listed thereon as the owner thereof (the “Joint Venture Property Owner”). The Fee Owned Properties and all of the right, title and interest of the Company or its Affiliate (the “Joint Venture Interest Owner”) in the Joint Venture Owned Property (the “Joint Venture Interest”) shall be conveyed to one (1) or more entities designated by Prudential (each such entity, a “Transferee”) in accordance with the terms of this Agreement. The Fee Owned Properties, the identity of which may change as described in Section 5 of this Agreement, are more particularly described below and are referred to in this Agreement with the following and with the Joint Venture Interest, collectively, as the “Specified Assets”:

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     Section 4      Conveyance of Specified Assets and Joint Venture Interest; Specified Assets Purchase Price .     On the business day immediately preceding the Closing Date (such business day, the “Specified Assets Closing Date”), Company L.P. shall cause to be conveyed by each Property Owner and the Joint Venture Interest Owner to the applicable Transferee(s) such Property Owner’s Specified Asset(s). The closing under this Section 4 (the “Specified Assets Closing”) shall take place at the offices of Pepper Hamilton LLP, Philadelphia, Pennsylvania. Each such conveyance by a Property Owner shall be made by delivery and recordation of a deed in the applicable form of Exhibit D hereto (each, a “Deed”) and delivery and recordation, if applicable, of the other documents and instruments listed in Section 6 . The conveyance of the Joint Venture Interest by the Joint Venture Interest Owner shall be made by delivery of an assignment of interest in the form of Exhibit E hereto (the “Assignment of Interest”). In exchange for the conveyance of all of the Specified Assets in accordance with the terms of this Section, Prudential shall pay or cause to be paid to Company L.P. the sum of $747,650,417 (the “Specified Assets Purchase Price”), subject to adjustment as provided in this Agreement and less the outstanding balance of any indebtedness on any of the Specified Assets or the Joint Venture Owned Property that is not repaid in full on or before the Closing Date. The Specified Assets Purchase Price, as adjusted as provided herein, shall be paid by wire transfer of immediately available funds pursuant to wiring instructions provided by Company L.P. to Prudential in writing not less than two (2) business days prior to the Specified Assets Closing Date.

     Section 5      Change in Specified Assets .     Company L.P. and Other Seller acknowledge and agree that Prudential has certain rights under the Master Agreement to modify the list of properties included in Specified Assets, including, without limitation, to drop or substitute the Joint Venture Interest from the transactions contemplated hereby and by the Master Agreement. Company L.P. and Other Seller further acknowledge and agree that Prudential shall have the right under this Agreement to modify the list of properties included in the Specified Assets, including without limitation, to drop or substitute the Joint Venture Interest if it does so under the Master Agreement, by delivering written notice thereof to Company L.P. or Other Seller, as the case may be. Upon each such modification and substitution, “Specified Assets” as used in this Agreement shall be deemed to include the then-current list of Specified Assets, as so modified and “Joint Venture Interest” shall be dropped from this Agreement or modified, as the case may be, in accordance with the terms hereof. Notwithstanding anything to the contrary in this Agreement, no Seller shall be required to convey any real property interest in a Specified Asset other than those listed in Exhibit A and Exhibit B as of the date of this Agreement unless and until either (a) any tenant or other party having a right to purchase such property or having another purchase-related right (such as to approve the property purchaser) has waived such party's rights, such rights have expired or Seller can otherwise convey the real property without violating such tenant's or other party's rights, or (b) Prudential shall have agreed to indemnify Seller for any loss, cost or damages relating to the applicable matter set forth in item (a) of this sentence.

     Section 6      Delivery of Documents by Company L.P.      On the Specified Assets Closing Date, Company L.P. and Other Seller shall, notwithstanding anything to the contrary, deliver or cause to be delivered to Prudential the following:

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