List of the interested companies who submitted EOIs for Rayis – Rabigh IWTP Project. A total of 31 companies including 14 Saudi companies expressed their interest in the Project as follows:
| EOI # | Interested Party |
| 1 | Abdul Aziz Al Ajlan Sons Co. for Commercial & Real Estate Investment – Ajlan & Bros |
| 2 | Abdullah Fahad Al-Khaledi for General Contracting Company (AFAC) |
| 3 | Abengoa Agua S.A. |
| 4 | Abu Dhabi National Energy Company, PJSC (TAQA) |
| 5 | Acciona Agua S.A. |
| 6 | Al-Fahd Company Trading Industries & Contracting |
| 7 | Alghanim International General Trading & Contracting Co. W.L.L |
| 8 | Alkhorayef Water & Power Technologies |
| 9 | Al-Rawaf Co. for Trading & Contracting |
| 10 | China Harbour Engineering Company Ltd (CHEC) |
| 11 | China Railway Construction Corporation (International) Limited |
| 12 | Civil Works Company Ltd. |
| 13 | Cobra Instalaciones y Servicios, S.A. (Cobra group) |
| 14 | FAS Energy |
| 15 | Gulf Investment Corporation G.S.C. (GIC) |
| 16 | Hassan Allam Holding S.A.E. (HAH) |
| 17 | Lamar Holding W.L.L |
| 18 | Marubeni Corporation |
| 19 | Mowah Co. (CJSC) |
| 20 | Mutlaq Al-Ghowairi Company (MGC) |
| 21 | Nesma Co. Ltd. |
| 22 | PASSAVANT Energy & Environment GmbH |
| 23 | Power and Water Utility Company for Jubail and Yanbu (MARAFIQ) |
| 24 | Powerchina International Group Limited |
| 25 | Tamasuk Holding Company |
| 26 | Tanqia Environment |
| Petrojet | |
| 27 | Taqqat Global Company |
| 28 | TECTON Engineering & Construction Saudi Contracting Company |
| 29 | UTICO FZC |
| 30 | Vision International Investment Company |
| 31 | A. Hak Pijpleidingen Saudi Company Limited |
