| AGL Resources | AMR Pipeline |
|---|---|
| Arkla | Bay Gas Storage |
| Boardwalk Pipeline | Brazos Port Water Authority |
| Caledonia Energy | CenterPoint Energy |
| Chemex | Chevron Pipeline |
| Cheyenne Plains Pipeline | Coastal |
| Colonial Pipeline | Colorado Interstate Gas |
| Columbia Gas Transmission | Columbia Gulf |
| Dominion Transmission, Inc. | Duke |
| East Tennessee Natural Gas | El Paso |
| Enbridge | Energy Transfer |
| Equilon | Equitable Gas |
| Express Pipeline | Exxon |
| Falcon Gas | Florida Gas |
| Gulfstream Pipeline | Houston Pipeline |
| IES Utilities | Jonah Gas |
| Kinder Morgan | Liberty Gas |
| Lone Star Gas | Maritimes & Northeast Pipeline |
| Market Hub Partners | MidAmerican Energy |
| Mobil | Natural Gas Clearing House |
| NGLP | Northern Border Pipeline |
| Northern Natural Gas | Oklahoma Gas Pipeline |
| Oxychem | Panhandle Eastern Pipeline |
| PetroLogistics | Phillips |
| Placid Oil | Rockies Express Pipeline |
| Seminole Pipeline | SISCORP |
| Southern Natural Gas | Spectra Energy |
| TC Energy | Tennessee Gas Pipeline |
| Teppco | Terasen Pipeline |
| Texas Eastern Transmission | Texas Gas Transmission |
| TransCanada | Transcontinental Gas Pipeline |
| Trinity Gas Storage | Trunkline Gas |
| Union Texas Petroleum | United Gas Pipeline |
| United Texas Transmission | Universal Compression |
| Valero | Williams Field Services |