Corporate Office Properties Trust Inc. (COPT) (NYSE: OFC) is a publicly traded real estate investment trust (REIT) corporation that specializes in office development, and describes itself as "a fully integrated, self-managed real estate investment trust that focuses on the acquisition, development, ownership, management and leasing of suburban office properties primarily in select Mid-Atlantic submarkets." Company headquarters is in Columbia, Maryland. Founded in 1988, by Clay W. Hamlin III and Jay H. Shidler, the company was based in Philadelphia, Pennsylvania. On Sept. 29, 1998, COPT merged with Constellation Energy (NYSE: CEG) a fortune 200 company and former subsidiary of Baltimore Gas and Electric. Following the merger, COPT focused aggressively on property in Howard County, Maryland. In 2005, the Washington Post named this company one of the "Top 125 Companies" in the Washington DC area.