Corporate Office Properties Trust Leases 73,000 Square Feet of Development Space in Colorado Springs, Colorado.

COLUMBIA, Md. -- Corporate Office Properties Trust (COPT) (NYSE:OFC) announced today the leasing of 73,000 square feet of new office development in Colorado Springs, Colorado. The first lease with Plasmon LMS, Inc. (LSE:PLM) is in a building located at 9925 Federal Drive, known as InterQuest Hybrid II, within the InterQuest Office Park. The InterQuest Office Park is located along the I-25 northeast submarket of Colorado Springs, Colorado.

Plasmon leased 44,000 square feet of the approximately 54,000 square feet located in InterQuest Hybrid II which has an anticipated completion date of third quarter 2008. Plasmon has a scheduled occupancy date of July 2008.

Plasmon has been the trusted source for professional archive solutions with commercial and public sector organizations worldwide for more than 20 years, seeking better suited smaller space and configuration to align with their OSCA program. Their solutions enable companies to meet regulatory obligations and manage risk associated with record retention, while providing competitive advantage through fast access to archived data.

ITT Corporation, Systems Division (NYSE:ITT) expanded its lease to occupy the entire building located at 655 Space Center Drive, known as Patriot Park VI, within Patriot Park in Colorado Springs, Colorado. Patriot Park is located at the intersection of two major thoroughfares, Powers Boulevard and Highway 24, and is adjacent to Peterson Air Force Base.

ITT previously leased 75,000 square feet of the approximately 104,000 square foot building in December 2007 and will now take occupancy of the entire Patriot Park VI building. ITT will take full occupancy by June 2008.

ITT Systems Division, based in Colorado Springs, CO., is a world leader in systems support and technical solutions for today's military and government partners.

"The leasing of this new development space is a testament to the current demand for new construction existing in Colorado Springs," stated Randall M. Griffin, President and Chief Executive Officer for Corporate Office Properties Trust. "We are extremely pleased to announce that Patriot Park VI is fully leased and that Hybrid II is almost fully leased, improving our already strong leasing percentage in Colorado Springs," he added.

Company Information

Corporate Office Properties Trust (COPT) (NYSE:OFC) is a specialty office real estate investment trust (REIT) that focuses on strategic customer relationships and specialized tenant requirements in the U.S. Government, Defense Information Technology and Data sectors. The Company acquires and develops properties which are typically concentrated in large office parks primarily located adjacent to government demand drivers and/or in growth corridors. As of December 31, 2007, the Company owned 246 office and data properties totaling 18.6 million rentable square feet, which includes 18 properties totaling 806,000 square feet held through joint ventures. The Company's portfolio primarily consists of technically sophisticated buildings in visually appealing settings that are environmentally sensitive, sustainable and meet unique customer requirements. More information on COPT can be found 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;

* 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, 2007.