EXHIBIT 21 EQUITABLE RESOURCES, INC. AND SUBSIDIARY COMPANIES AS OF DECEMBER 31, 1998 EQT Capital Corporation Equitable Energy, L.L.C. Equitable Power Services Company Equitable Production Company Equitrans, L.P. EREC Canada Ltd. EREC Nevada, Inc. EREC Properties. L.L.C. ERI Global Partners, Inc. ERI Holdings ERI Holdings II ERI Investments, Inc. ERI JAM, LLC ERI Power Services Canada Ltd. ERI Providence, L.L.C. ERI Services Canada Ltd. ERI Services, Inc. ERI Services (St. Lucia) Limited ET Avoca Company ET Blue Grass Company 420 Energy Investments, Inc. IEC Hunterdon, Inc. IEC Management Services, Inc. IEC Montclair, Inc. IEC Plymouth, Inc. Independent Energy Corporation Independent Energy Finance Corporation Independent Energy Operations, Inc. Kentucky West Virginia Gas Company, L.L.C. Nora Transmission Company Northeast Energy Services, Inc. Three Rivers Pipeline Corporation