| ABB | ENEL | KVAERNER | QATAR GENERAL PETROLEUM |
| ADNOC | ENEL GREEN POWER | LUMMUS | RUHRGAS |
| AGIP | EXXON | MANNESMANN | SAIPEM |
| ALSTOM POWER | FISIA ITALIMPIANTI | MAN TURBO | SHELL |
| ANSALDO | FINCANTIERI | MOBIL | SIEMENS |
| BASF | FLUOR DANIEL | NAOC | SNAM |
| BECHTEL | FOSTER WHEELER | NESTE OY | SNAM PROGETTI |
| BP | GENERAL ELECTRIC | NIGC | SONATRACH |
| DONGFANG STEAM TURBINE | HYUNDAI | NIOC | SWCC |
| DOOSAN HEAVY INDUSTRIES | JOHN BROWN | NUOVO PIGNONE | TECHNIP |
| ELF AQUITAINE NORGE | KELLOG | PEMEX | TECHINT |
| EDIPOWER | KEPCO | PETROBRAS | TECNIMONT |
| EDISON | KUWAIT NAT. PETROLEUM | PETROLEUM DEVELOP. OMAN | THERMODYN |
| ENIPOWER | KUWAIT OIL COMPANY | PETROVIETNAM | UHDE |
