Corporate Office Properties Trust Announces Fourth Quarter and Year End 2009 and 2010 Quarterly Earnings Conference Calls

Please use the following link to pre-register and view important information about this conference call. Pre-registering is not mandatory but is recommended as it will provide you immediate entry into the call and will facilitate the timely start of the conference. Pre-registration only takes a few moments and you may pre-register at anytime, including up to and after the call start time. To pre-register, please click on the below link:

https://www.theconferencingservice.com/prereg/key.process?key=PXUDU6UW7

You may also pre-register in the Investor Relations section of the Company's website at www.copt.com. Alternatively, you may be placed into the call by an operator by calling the number provided above at least 5 to 10 minutes before the start of the call. A replay of this call will be available beginning Thursday, February 11 at 2:00 p.m. Eastern Time through Thursday, February 25 at midnight Eastern Time. To access the replay within in the United States, please call 888-286-8010 and use passcode 38751918. To access the replay outside the United States, please call 617-801-6888 and use passcode 38751918.

Please use the following link to pre-register and view important information about this conference call. Pre-registering is not mandatory but is recommended as it will provide you immediate entry into the call and will facilitate the timely start of the conference. Pre-registration only takes a few moments and you may pre-register at anytime, including up to and after the call start time. To pre-register, please click on the below link:

https://www.theconferencingservice.com/prereg/key.process?key=P9AH3ECQC

You may also pre-register in the Investor Relations section of the Company's website at www.copt.com. Alternatively, you may be placed into the call by an operator by calling the number provided above at least 5 to 10 minutes before the start of the call. A replay of this call will be available beginning Thursday, April 29 at 2:00 p.m. Eastern Time through Thursday, May 13 at midnight Eastern Time. To access the replay within in the United States, please call 888-286-8010 and use passcode 22745357. To access the replay outside the United States, please call 617-801-6888 and use passcode 22745357.

The conference calls will also be available via live webcast in the Investor Relations section of the Company's website at www.copt.com. A replay of the conference calls will be immediately available via webcast in the Investor Relations section of the Company's website.

Please use the following link to pre-register and view important information about this conference call. Pre-registering is not mandatory but is recommended as it will provide you immediate entry into the call and will facilitate the timely start of the conference. Pre-registration only takes a few moments and you may pre-register at anytime, including up to and after the call start time. To pre-register, please click on the below link:

https://www.theconferencingservice.com/prereg/key.process?key=PU738Q8YR

You may also pre-register in the Investor Relations section of the Company's website at www.copt.com. Alternatively, you may be placed into the call by an operator by calling the number provided above at least 5 to 10 minutes before the start of the call. A replay of this call will be available beginning Thursday, July 29 at 3:00 p.m. Eastern Time through Thursday, August 12 at midnight Eastern Time. To access the replay within in the United States, please call 888-286-8010 and use passcode 67473908. To access the replay outside the United States, please call 617-801-6888 and use passcode 67473908.

The conference calls will also be available via live webcast in the Investor Relations section of the Company's website at www.copt.com. A replay of the conference calls will be immediately available via webcast in the Investor Relations section of the Company's website.

Please use the following link to pre-register and view important information about this conference call. Pre-registering is not mandatory but is recommended as it will provide you immediate entry into the call and will facilitate the timely start of the conference. Pre-registration only takes a few moments and you may pre-register at anytime, including up to and after the call start time. To pre-register, please click on the below link:

https://www.theconferencingservice.com/prereg/key.process?key=P4J9NCBW8

You may also pre-register in the Investor Relations section of the Company's website at www.copt.com. Alternatively, you may be placed into the call by an operator by calling the number provided above at least 5 to 10 minutes before the start of the call. A replay of this call will be available beginning Thursday, October 28 at 3:00 p.m. Eastern Time through Thursday, November 11 at midnight Eastern Time. To access the replay within in the United States, please call 888-286-8010 and use passcode 90157200. To access the replay outside the United States, please call 617-801-6888 and use passcode 90157200.

The conference calls will also be available via live webcast in the Investor Relations section of the Company's website at www.copt.com. A replay of the conference calls will be immediately available via webcast in the Investor Relations section of the Company's website.

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, develops, manages and leases properties which are typically concentrated in large office parks primarily located adjacent to government demand drivers and/or in growth corridors. As of September 30, 2009, the Company owned 265 office and data properties totaling 19.4million rentable square feet, which includes 19 properties totaling 989,000 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. COPT is an S&P MidCap 400 company and more information 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 1A of the Company's Annual Report on Form 10-K for the year ended December 31, 2008.

SOURCE: Corporate Office Properties Trust (COPT)

Corporate Office Properties Trust (COPT)
Mary Ellen Fowler
Senior Vice President and Treasurer
443-285-5450
maryellen.fowler@copt.com