COPT to Develop Second Building with 110,000 Square Feet for UMBC's Research and Technology Park, bwtech@UMBC.

BALTIMORE & COLUMBIA, Md. -- The University of Maryland, Baltimore County's on-campus research and technology park, bwtech@UMBC and Corporate Office Properties Trust (COPT)(NYSE:OFC), one of the region's largest suburban office companies, announced today that COPT will build and own a second building of 110,000 square feet in a four-story office building located at 5520 Research Park Drive on ground leased from the UMBC Research Park Corporation located within the research and technology park, bwtech@UMBC. Large and small technology companies will be targeted as tenants of the office building. The total construction cost of the project is projected to be approximately $22 million.

"We are very pleased to further our relationship with UMBC by being given the opportunity to develop a second building for their expanding research and technology park and to create more critical mass for COPT within the park," stated Randall M. Griffin, President and CEO of Corporate Office Properties Trust.

This building will be adjacent to a development project recently announced within bwtech@UMBC which is the 23,500 square foot new home for the U.S. Geological Survey (USGS) Maryland-Delaware-District of Columbia Water Science Center located at 5522 Research Park Drive. This would bring COPT's total square foot ownership in the park to 133,900 square feet.

bwtech@UMBC was Maryland's first university research park and is the only research and development park in Baltimore County. The 41-acre park's first building, completed in 2001, is occupied by RWD Technologies. A second building, completed in 2004, is fully leased.

About COPT: Corporate Office Properties Trust (COPT) is a fully integrated, self-managed real estate investment trust (REIT) that focuses on the ownership, management, leasing, acquisition and development of suburban office properties located primarily in submarkets within the Greater Washington, DC region. As of December 31, 2005, the Company owned 183 office properties totaling 14.6 million rentable square feet, which included 18 properties totaling 885,000 square feet held through joint ventures. The Company has implemented a core customer expansion strategy that is built around meeting, through acquisitions and development, the multi-location requirements of the Company's existing strategic tenants. The Company's property management services team provides comprehensive property and asset management to company owned properties and select third party clients. The Company's development and construction services team provides a wide range of development and construction management services for company owned properties, as well as land planning, design/build services, consulting, and merchant development to select third party clients. 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.

About bwtech@UMBC: bwtech@UMBC is a 41-acre research and technology community at the University of Maryland, Baltimore County (UMBC). bwtech@UMBC has a total development capacity of up to 330,000 square feet of office and laboratory space. The USGS building will be the third of five planned state-of-the-art buildings containing over 300,000 square feet of office and wet lab space. The park's 62,000 square-foot first building has been leased by the information technology firm RWD Technologies since 2001. The second building, a 60,000-square-foot multi-tenant building, is fully leased with tenants including The NASA Goddard Earth Sciences and Technology Center, software maker BD Metrics Inc., healthcare media and education firm Med-IQ, the Erickson School of Aging Studies at UMBC, the engineering/design firm Edwards & Kelcey, and UMBC's Alex. Brown Center for Entrepreneurship.

UMBC began planning for a new research and technology park in the early 1990s, based on the success of other U.S. parks and the vision of the late Michael Hooker, UMBC president from 1986-1992. To date, UMBC's research park and technology incubator have received public and private sector funding from the Maryland Economic Development Corporation (MEDCO), the State of Maryland, the City of Baltimore, Baltimore County, the U.S. Department of Commerce, The Abell Foundation, and the Maryland Technology Development Corporation (TEDCO.) bwtech@UMBC is part of Baltimore County's Southwest Enterprise Zone, making companies moving to the park eligible for credits on real property and income taxes, as well as credits for job creation.

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;

--our ability to satisfy and operate effectively under federal income tax rules relating to real estate investment trusts and partnerships;

--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 the Company's filings with the Securities and Exchange Commission, particularly the section entitled "Risk Factors" in Item 1 of the Company's Annual Report on Form 10-K for the year ended December 31, 2005.