(a)     Revolving Credit Facility Agreement.

     On December 22, 2005, we, together with Brandywine Operating Partnership, L.P., the partnership through which we own our assets and conduct our business, entered into a credit agreement (the “Revolving Credit Facility Agreement”) that provides for an unsecured, revolving credit facility (the “Revolving Credit Facility”) in an initial amount of $600 million, which amount may be increased at our option to a maximum of $800 million. The Revolving Credit Facility Agreement provides for a letter of credit sub-facility of $65 million.

     The term of the Revolving Credit Facility is 48 months, subject to one 12-month extension. Loans under the Revolving Credit Facility bear interest at a per annum floating rate equal to: (i) the higher of (x) the prime rate or (y) the federal funds rate plus 0.50% per annum, plus, in either case, 0.25% or (ii) a London interbank offered rate that is the rate at which Eurodollar deposits for one, two, three or six months are offered plus between 0.55% and 1.10% per annum (the “Libor Margin”), depending on our debt rating. Alternatively, so long as we maintain an investment grade rating, we may request competitive bids from the Lenders for a Libor Margin to be applicable for a period of one, two or three months with respect to loans under the Revolving Credit Facility up to 50% of the aggregate facility amount. We have agreed to pay a facility fee at a rate of between 0.15% and 0.25% per annum, depending on our debt rating.

     The Revolving Credit Facility Agreement contains financial and operating covenants. Financial covenants include minimum net worth, minimum interest coverage and fixed charge coverage ratios, maximum leverage ratio, restrictions on unsecured and secured debt as a percentage of unencumbered assets, and other financial tests. Operating covenants include limitations on our ability to incur additional indebtedness, grant liens on assets, enter into affiliate transactions, pay dividends, make acquisitions and investments and construct or develop new properties.

     JPMorgan Chase Bank, N.A. serves as Administrative Agent, Swing Lender and Issuing Lender, Bank of America, N.A. serves as Syndication Agent and Issuing Lender, and Citizens Bank of Pennsylvania, Wachovia Bank, National Association, and Wells Fargo Bank, National Association serve as Co-Documentation Agents under the Revolving Credit Agreement.

     A copy of the Revolving Credit Facility Agreement is attached as an exhibit to this Current Report. The description of the Revolving Credit Facility Agreement does not purport to be complete and is qualified by reference to the copy of the Revolving Credit Facility Agreement attached as an exhibit.

     (b)     Release of Subsidiary Guarantees.

     (i)      Certain of the wholly-owned subsidiaries of Brandywine Operating Partnership, L.P. (collectively, “Subsidiary Guarantors”) executed guarantees of payment of principal and interest on Brandywine Operating Partnership’s $275,000,000 4.50% Guaranteed Notes due 2009 and $250,000,000 5.40% Guaranteed Notes due 2014 (collectively, the “2009/2014 Notes”). In addition, the Subsidiary Guarantors executed guarantees of payment of principal and interest on Brandywine Operating Partnership’s $300,000,000 5.625% Guaranteed Notes due 2010 (the “2010 Notes”). The Indenture dated as of October 22, 2004, as supplemented by the First Supplemental Indenture dated as of May 25, 2005 (the “Indenture”) under which the 2009/2014 Notes and 2010 Notes were issued provides for the automatic release of the guarantees of the Subsidiary Guarantors with respect to the 2009/2014 Notes and 2010 Notes upon the release of guarantees delivered by the Subsidiary Guarantors under Brandywine Operating Partnership’s principal credit agreement. Because the guarantees by the Subsidiary Guarantors of Brandywine Operating Partnership’s principal credit agreement were terminated in conjunction with our entry into the Revolving Credit Agreement, the guarantees of the 2009/2014 Notes and 2010 Notes by the Subsidiary Guarantors were terminated.