EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT* JURISDICTION OF INCORPORATION ------------- Constellation Holdings, Inc. ..................................................................... Maryland Constellation Investments, Inc. .................................................................. Maryland Constellation Energy Source, Inc. (formerly named BNG, Inc.)...................................... Delaware Safe Harbor Water Power Corporation............................................................... Pennsylvania BGE Home Products & Services, Inc................................................................. Maryland BGE Energy Projects & Services, Inc............................................................... Maryland *The names of certain indirectly owned subsidiaries have been omitted because, considered in the aggregate as a single subsidiary, they would not constitute a significant subsidiary pursuant to Rule 1-02(w) of Regulation S-X. 83