| Air Liquide |
| Atlantic |
| Caribbean Gas Chemicals Ltd |
| Caribbean Industrial Gases Unlimited |
| Guaracara Refining |
| Massy Gas Products |
| Methanex Trinidad Limited |
| Methanol Holdings (Trinidad) Ltd |
| National Energy Corporation of Trinidad & Tobago Limited |
| National Gas Company of Trinidad & Tobago |
| Niquan Energy |
| NuIron (under regulation 3(2) ap) |
| Nutrien |
| Paria Fuel Trading Company Ltd |
| Phoenix Park Gas Processors Ltd |
| Point Lisas Industrial Port Development Company Limited
(PLIPDECO) |
| Power Generation Company of Trinidad & Tobago Limited |
| Proman/Industrial Plant Services Limited |
| Pt. Lisas Nitrogen Limited |
| Trinidad Generation Unlimited (TGU) |
| Trinity Power Limited |
| Yara Trinidad Limited |
| BHP Billiton Trinidad & Tobago |
| bp Trinidad & Tobago LLC |
| Columbus Energy Resources |
| DeNovo Energy Limited |
| EOG Resources Trinidad Limited |
| Heritage Petroleum Company Limited |
| Lease Operators Limited |
| Perenco |
| Range Resources Trinidad Limited |
| Repsol |
| Shell Trinidad Limited |
| Touchstone Exploration (Trinidad) Ltd |
| A & V Oil and Gas Ltd |
| Advance Oil Co. Ltd |
| API Petroleum Company Ltd |
| East Coast Drilling & Workover Services Ltd |
| Fram Exploration (Trinidad) Ltd |
| Goudron E & P Limited |
| Hydrocarb Petroleum Limited |
| Jasmin Oil & Gas Ltd. |
| Krishna Persad & Associates |
| Moonsie Oil Company Limited |
| New Horizon Exploration Trinidad and Tobago Unlimited |
| Oilbelt Services Limited |
| Petroleum Contracting Services Limited |
| Rocky Point (Trinidad & Tobago) Limited |
| T.N. Ramnauth & Company Limited |
| Trinidad Wireline Limited |
