Corporate Office Properties Trust Completes Sale of 2.75 Million Common Shares.

Business Editors/Real Estate Writers

COLUMBIA, Md.--(BUSINESS WIRE)--April 26, 2004

Corporate Office Properties Trust (NYSE:OFC) announced today that it completed the sale of 2,750,000 common shares of beneficial interest. Wachovia Securities purchased the shares as the underwriter in connection with the public offering of these securities. The sale generated net proceeds to the Company of approximately $58.4 million.

Company Information

Corporate Office Properties Trust is a fully integrated, self-managed, real estate investment trust which focuses on the ownership, management, leasing, acquisition and development of suburban office properties located in select Mid-Atlantic submarkets. The Company currently owns 130 office properties totaling 10.8 million rentable square feet, including one property held through a joint venture. Corporate Development Services provides a wide range of development and construction management services. In addition, Corporate Office Services provides land planning, design/build services, consulting and merchant development to third party entities. The Company's shares are traded on the New York Stock Exchange under the symbol OFC. More information on Corporate Office Properties Trust can be found on the Internet at www.copt.com.

Forward-Looking Information

This press release may contain "forward-looking" statements, as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, that are based on the Company's current expectations, estimates and projections about future events and financial trends affecting the Company. Forward-looking statements can be identified by the use of words such as "may", "will", "should", "expect", "estimate" or other comparable terminology. Forward-looking statements are inherently subject to risks and uncertainties, many of which the Company cannot predict with accuracy and some of which the Company might not even anticipate. Accordingly, the Company can give no assurance that these expectations, estimates and projections will be achieved. Future events and actual results may differ materially from those discussed in the forward-looking statements.

Important factors that may affect these expectations, estimates, and projections include, but are not limited to:

-- the Company's ability to borrow on favorable terms;

-- general economic and business conditions, which will, among

other things, affect office property demand and rents, tenant

creditworthiness, interest rates and financing availability;

-- adverse changes in the real estate markets including, among

other things, increased competition with other companies;

-- risk of real estate acquisition and development, including,

among other things, risks that development projects may not be

completed on schedule, that tenants may not take occupancy or

pay rent or that development or operating costs may be greater

than anticipated;

-- risks of investing through joint venture structures, including

risks that the Company's joint venture partners may not

fulfill their financial obligations as investors or may take

actions that are inconsistent with the Company's objectives;

-- governmental actions and initiatives;

-- and environmental requirements.

The Company undertakes no obligation to update or supplement any forward-looking statements. For further information, please refer to our filings with the Securities and Exchange Commission, particularly the section entitled "Risk Factors" in Item 1 of our Annual Report on Form 10-K for the year ended December 31, 2003.