The company operated over 35 power plants in 11 states (mainly Maryland, Pennsylvania, New York, West Virginia, and California) under its operating and holding company Constellation Energy Group. Constellation Energy's regulated utility, Baltimore Gas and Electric Company (BGE), operated in central Maryland. BGE created Constellation as a holding company in 1999.[2] Constellation Energy was a Fortune 500 company and was one of the top electricity producers in the United States.