EX-21 4 0004.txt SUBSIDIARIES OF THE COMPANY SUBSIDIARIES OF THE COMPANY Exhibit 21 Name State or Country of Incorporation Atlantic Gas Corporation Delaware Energia Estrella del Sur, S. A. de C. V. Mexico Enhanced Service Systems, Inc. Delaware KellAir Aviation Company Delaware KellAir NC Aviation Company North Carolina Keystone Pipeline Services, Inc. Delaware Mercado Gas Services Inc. Delaware Norteno Pipeline Company Delaware PEI Power Corporation Pennsylvania PG Energy Services, Inc. Pennsylvania Southern Transmission Company Delaware Southern Union Energy International, Inc. Delaware Southern Union Financing I Delaware Southern Union International Investments, Inc. Delaware Southern Union Technology Partners, L. P. Southern Union Total Energy Systems, Inc. Delaware SUPro Energy Company Delaware Sygent, Inc. Delaware Note: Fifteen other wholly-owned subsidiaries of Southern Union Company, ConTigo, Inc. (a Delaware corporation), Energy WorX, Inc. (a Delaware corporation), GUS Acquisition Corporation (a Rhode Island corporation), Honesdale Gas Company (a Pennsylvania corporation), PG Energy, Inc. (a Pennsylvania corporation), Penn Gas Development Company (a Pennsylvania corporation), Pennsylvania Energy Resources, Inc. (a Pennsylvania corporation), Southern Union Financing II (a Delaware business trust), Southern Union Financing III (a Delaware business trust), Southern Union Gas Company, Inc. (a Delaware corporation), Southern Union Gas Company, Inc. (a Texas corporation), SU Acquisition Corporation (a California corporation), SUG Acquisition Corporation (a Rhode Island corporation), Western Utilities, Inc. (a Delaware corporation) and Western Utilities, Inc. (a New Mexico corporation), conduct no business except to the extent necessary to maintain their corporate name or existence.