| Saudi Aramco |
Saudi Aramco Total Refining & Petrochemical Company (SATORP) |
| Saudi Basic Industries Corporation (SABIC) |
Saline Water Conversion Corporation (SWCC) |
| Saudi Electricity Company |
Saudi Arabian Mining Company (MA'ADEN) |
| Saudi International Petrochemical Company (Sipchem) |
Kuwait Oil Company |
| Technip |
Petrofac |
| Maire Tecnimont |
Tecnicas Reunidas |
| Samsung Engineering |
Rotary Engineering Limited |
| JGC Corporation |
Saipem |
| KBR |
CTCI (Thailand) Co. Ltd. |
| Mitsubishi Heavy Industries Ltd. |
Aker Solutions |
| CMI Energy |
Bechtel |
| The Shaw Group Inc |
Lurgi |
| Linde |
Callidus Technologies |
| Aquatech |
Sinopec |
| Flour |
Techint |
