AEP ENERGY SERVICES, INC
AMERICAN CENTRAL GAS COMPANIES, INC.
ASSOCIATED ELECTRIC COOPERATIVE, INC.
BLACK HILLS ENERGY RESOURCES INC
BP ENERGY COMPANY
CARGILL,INC.
COWBOY PIPELINE SERVICE COMPANY
DELMARVA POWER & LIGHT COMPANY
DOMINION EXPLORATION & PRODUCTION, INC.
E PRIME INC
ENDEVCO OIL AND GAS COMPANY
ENERCORP GAS TRANSMISSION SYSTEM, INC.
ENERGYUSA-TPC CORP
FERRELL RESOURCES, L.L.C.
FLT ENERGY SERVICES, LLC
H & N GAS LTD
J. MAKOWSKI ASSOCIATES, INC
KCS ENERGY MARKETING, INC.
LUMINANT ENERGY COMPANY LLC
MOBIL NATURAL GAS INC.
MUNICH RE TRADING LLC
NJR ENERGY SERVICES COMPANY, LLC
NOBLE ENERGY, INC.
ORANGE AND ROCKLAND UTILITIES, INC.
PEPCO ENERGY SERVICES, INC.
STATOIL NORTH AMERICA INC
TENASKA GAS STORAGE,LLC
THE NARRAGANSETT ELECTRIC COMPANY D/B/A RHODE ISLAND ENERGY
YUMA GAS CORPORATION