AES Corporation

Aggreko Plc

Allegheny Energy, Inc.

Ameren Corporation

American Electric Power Company, Inc.

American States Water Company

American Water Works Company, Inc.

Aquila, Inc.

Associated Natural Gas Corporation

Atlanta Gas Light Company

Atmos Energy Corporation

Avista Corporation

Baltimore Gas and Electric Company

Bay State Gas Company

Bayernwerk AG

Bewag AG

Big Rivers Electric Corporation

Black Hills Corporation

Bonneville Power Administration

Boston Edison Company

Bouygues S.A.

British Energy Plc

CMS Energy Corporation

California Water Service Group

Calpine Corporation

Canadian Utilities Limited

Cap Rock Energy Corporation

Carolina Power & Light Company

Cascade Natural Gas Corporation

Central Vermont Public Service Corporation

Centrica plc

Chesapeake Utilities Corporation

Chubu Electric Power Company, Inc.

Chugoku Electric Power Company Inc.

Cleco Corporation

Cogentrix Energy, Inc.

Commonwealth Energy System

Companhia Energética de Minas Gerais S.A. CEMIG

Connecticut Light and Power Co.

Consolidated Edison, Inc.

Consolidated Natural Gas Company

Consumers Power Co.

Consumers Water Company

Covanta Energy Corporation

DTE Energy Company

Dalkia Holding

Destec Energy, Inc.

Dominion Resources, Inc.

Duke Energy Corporation



EPCOR Utilities Inc.

Edison International

El Paso Electric Company

El Paso Natural Gas Company

Electrabel N.V.

Electricidade de Portugal, S.A.

Electricity Generating Authority of Thailand (EGAT)

Electricité de France

Enbridge Inc.

Enersis S.A.

Enron Corporation

Entergy Corporation

Environmental Power Corporation

Equitable Resources, Inc.

Exelon Corporation

FPL Group, Inc.

Florida Progress Corporation

Florida Public Utilities Company

Fortis, Inc.

Fortum Corporation

GPU, Inc.

Gas Natural SDG S.A.

Gaz de France

Great Plains Energy Incorporated

Hawaiian Electric Industries, Inc.

Hokkaido Electric Power Company Inc. (HEPCO)

Hong Kong and China Gas Company Ltd.

Hongkong Electric Holdings Ltd.

Hyder plc


ITC Holdings Corp.

Iberdrola, S.A.

Idaho Power Company

Illinois Bell Telephone Company

Indiana Energy, Inc.

International Power PLC

KU Energy Corporation

Kelda Group plc

Kenetech Corporation

KeySpan Energy Co.

Korea Electric Power Corporation (Kepco)

LG&E Energy Corporation

MDU Resources Group, Inc.

Madison Gas and Electric Company

Magma Power Company

Maine & Maritimes Corporation

Manila Electric Company (Meralco)

Middlesex Water Company

Minnesota Power, Inc.

Montana Power Company

NRG Energy, Inc.

National Grid USA

National Power PLC

Nebraska Public Power District

Nevada Power Company

New Jersey Resources Corporation

Neyveli Lignite Corporation Ltd.

Niagara Mohawk Holdings Inc.

North West Water Group plc

NorthWestern Corporation

Northeast Utilities

Northern States Power Company

Northwest Natural Gas Company

Ontario Hydro Services Company

Osaka Gas Company, Ltd.

Otter Tail Power Company

PECO Energy Company

PG&E Corporation

PNM Resources Inc.

PPL Corporation


Pennon Group Plc

Philadelphia Suburban Corporation

Piedmont Natural Gas Company, Inc.

Pinnacle West Capital Corporation

Power-One, Inc.

PowerGen PLC

Powergen PLC

Public Service Company of New Hampshire

Public Service Enterprise Group Inc.

Puerto Rico Electric Power Authority

Puget Sound Energy Inc.

Questar Corporation

RAO Unified Energy System of Russia


Reliant Energy Inc.

Ruhrgas AG

SCANA Corporation

SEMCO Energy, Inc.

SJW Corporation

Salt River Project

Scarborough Public Utilities Commission

Scottish Hydro-Electric PLC

Scottish and Southern Energy plc

ScottishPower plc

Seattle City Light

Sempra Energy

Severn Trent PLC

Shikoku Electric Power Company, Inc.

South Jersey Industries, Inc.

Southern Electric PLC

Southern Indiana Gas and Electric Company

Southern Union Company

Southwest Gas Corporation

Southwest Water Company

Southwestern Electric Power Co.

Suez Lyonnaise des Eaux

TenneT B.V.

Tennessee Valley Authority

Texas Utilities Company

Thames Water plc

The Coastal Corporation

The Columbia Gas System, Inc.

The Empire District Electric Company

The Kansai Electric Power Company, Inc.

The Montana Power Company

The Southern Company

The United Illuminating Company

Tokyo Gas Co., Ltd.

Trigen Energy Corporation

UGI Corporation

Unicom Corporation

United Utilities PLC

United Water Resources, Inc.

Unitil Corporation

Utah Power and Light Company


Vattenfall AB

Viridian Group plc

WPS Resources Corporation

Warwick Valley Telephone Company

Washington Gas Light Company

Washington Natural Gas Company

Westar Energy, Inc.

Western Resources, Inc.

Wisconsin Energy Corporation

Wisconsin Public Service Corporation

Xcel Energy Inc.