Corporate Office Properties Trust Acquires 188,819 Square Feet in Columbia, Maryland

COLUMBIA, Md.--()--Sept. 20, 2005--Corporate Office Properties Trust (NYSE:OFC) announced today the $26.0 million acquisition of Gateway Crossing 95, consisting of six one-story office buildings containing 188,819 square feet located in the Columbia Gateway Business Park in Columbia, Maryland. The office buildings are located on Columbia Gateway Drive, positioned at the mid-point of Baltimore and Washington, D.C., near the intersection of MD Route 175 and Interstate 95.

7130 Columbia Gateway Drive contains 46,840 square feet, 7134 Columbia Gateway Drive contains 21,991 square feet, 7138 Columbia Gateway Drive contains 38,225 square feet, 7142/7146 Columbia Gateway Drive contains 45,951 square feet and 7150 Columbia Gateway Drive contains 35,812 square feet. The office buildings are 92% leased to eight tenants. The purchase was financed from proceeds from the Company's unsecured line of credit.

The acquisition of Gateway Crossing 95 adds to the Company's significant presence in the Columbia Gateway Business Park, a 630 acre business community where the Company now owns 23 office buildings totaling 1,340,124 square feet. The Company also has 2 office buildings under construction in the park totaling 210,106 square feet.

"We are pleased to increase our position in the Columbia Gateway Business Park, located within a core market for Corporate Office Properties," stated Randall M. Griffin, President and Chief Executive Officer for Corporate Office Properties Trust. "The Company now owns 46% of the office component of the largest business park in Howard County, Maryland," he added.

Company Information

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 primarily in select Mid-Atlantic submarkets. The Company is among the largest owners of suburban office properties in the Greater Washington, DC region. The Company currently owns 153 office properties totaling 12.5 million rentable square feet. 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.

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 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, 2004.

Contacts

Corporate Office Properties Trust
Mary Ellen Fowler, 410-992-7324
maryellen.fowler@copt.com

Contacts

Corporate Office Properties Trust
Mary Ellen Fowler, 410-992-7324
maryellen.fowler@copt.com