On October 25, 2012, Corporate Office Properties Trust (the "Registrant") issued a press release relating to its financial results for the three and nine months ended September 30, 2012 and, in connection with this release, is making available certain supplemental information pertaining to its properties and operations as of and for the period ended September 30, 2012. The earnings release and supplemental information are included as Exhibit 99.1 to this report and are incorporated herein by reference.

The information included herein, including the exhibits, shall not be deemed "filed" for any purpose, including the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or subject to liabilities of that Section. The information included herein, including the exhibits, shall also not be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended (the "Securities Act"), or the Exchange Act regardless of any general incorporation language in such filing.

(a) Financial Statements of Businesses Acquired

None

(b) Pro Forma Financial Information

None

(c) Shell Company Transactions

None

(d) Exhibits

Exhibit Number                                 Exhibit Title
          99.1       Corporate Office Properties Trust earnings release and
                     supplemental information for the period ended September 30, 2012,
                     including the press release dated October 25, 2012