Corporate Office Properties Trust Executes 91,839 Square Foot Lease With General Dynamics.

Business Editors

COLUMBIA, Md.--(BUSINESS WIRE)--May 10, 2000

Company leases 77% of 221 National Business Park building,

scheduled for late 2000 delivery

Corporate Office Properties Trust (NYSE: OFC) announced today the execution of a ten-year lease with General Dynamics Electronic Systems for 91,839 square feet of space at 221 National Business Park.

The four-story, 120,000 square foot Class A office building is located at the intersection of MD Route 295 and Route 32 in The National Business Park, the Company's 275-acre office park in Annapolis Junction, Maryland. Construction of the $18 million project has commenced, with delivery scheduled for late 2000.

The Electronic Systems division of General Dynamics (NYSE: GD) manufactures and supplies sophisticated defense systems and technologies to the United States and its allies. The company specializes in the development and operation of combat, marine and information systems and technology, as well as the aerospace industry.

More than 200 employees will work from The National Business Park location, with the majority focusing on research and development activities and technical support and applications.

Upon completion of 221 National Business Park, Corporate Office Properties will own eight Class A office buildings at The National Business Park, comprising more than 900,000 square feet of office space, of which 97% is currently leased. The Park also includes a full-service hotel and day-care center, and plans are under development for the construction of a small retail center.

"General Dynamics is a proven leader in the defense industry and represents an outstanding lead credit tenant for this building," stated Randall M. Griffin, President and Chief Operating Officer for Corporate Office Properties. "We were successful in winning their multi-site search by satisfying the customized needs of General Dynamics, demonstrating our ability to deliver this Class A building in a timely fashion and offering a range of value-added tenant services," he added.

Corporate Office Properties presently owns 45 office buildings, totaling more than 3.4 million square feet of space in the Baltimore/Washington corridor. The Company is the largest owner of office space in Anne Arundel County, with 32 buildings representing 59% of the BWI Airport submarket.

Corporate Development Services is overseeing construction management for 221 National Business Park, and Riparius Construction is the general contractor.

Company Information

Corporate Office Properties Trust is a fully-integrated, self-managed real estate investment trust which focuses on the ownership, development, management and acquisition of suburban office properties located in targeted suburban submarkets in the United States. The Company presently owns 78 office properties totaling 6.0 million square feet of space.

In addition, Corporate Development Services, the Company's development company, provides a wide range of development and construction management services. The Company's property management company, Corporate Realty Management, manages 16 million square feet for the Company and third parties. For more information, visit Corporate Office Properties' website at http://www.copt.com.

Forward-Looking Information

This press release contains forward-looking information based upon the Company's current best judgement and expectations. Actual results could vary from those presented herein. The risks and uncertainties associated with the forward-looking information include the strength of the commercial office real estate market in which the Company operates, competitive market conditions, general economic growth, interest rates and capital market conditions.

For further information, please refer to the Company's filings with the Securities and Exchange Commission.