On October 11, 2012, Corporate Office Properties Trust (the "Registrant") and Corporate Office Properties, L.P. (the "Operating Partnership") entered into an Underwriting Agreement (the "Underwriting Agreement") with Wells Fargo Securities, LLC, J.P. Morgan Securities LLC and Barclays Capital Inc., as representatives of the underwriters described therein (all such underwriters, collectively, the "Underwriters"), in connection with the issuance and sale of 7,500,000 shares of the Registrant's common shares of beneficial interest, par value $0.01 per share (the "Common Shares"). The Registrant also granted to the Underwriters an option to purchase up to 1,125,000 additional Common Shares, which has since been exercised. The Underwriting Agreement is attached to this report as Exhibit 1.1.

(d) Exhibits

Exhibit No.                                Exhibit Title

1.1            Underwriting Agreement, dated October 11, 2012, by and among Corporate
               Office Properties Trust, Corporate Office Properties, L.P., Wells
               Fargo Securities, LLC, J.P. Morgan Securities LLC and Barclays Capital
               Inc., as representatives of the underwriters described therein

5.1            Opinion of Saul Ewing LLP

8.1            Opinion of Morgan, Lewis & Bockius LLP

23.1           Consent of Saul Ewing LLP (included in Exhibit 5.1)

23.2           Consent of Morgan, Lewis & Bockius LLP (included in Exhibit 8.1)

99.1           Press Release dated October 11, 2012