| GASCO ASIA LIMITED | Private company limited by shares | Dissolved |
| GASCO ASSET INVESTMENTS LIMITED | Private company limited by shares | Live |
| GASCO HONG KONG (1984) LIMITED | Private company limited by shares | Dissolved |
| Gasco Petroleum International Limited | Private company limited by shares | Live |
| GASCO INVESTMENTS LIMITED | Public company limited by shares | Dissolved |
| L.P. GASCO LIMITED | Private company limited by shares | Live |
| Gasco Petroleum Limited | Private company limited by shares | Live |
| GASCOIGNE LIMITED | Private company limited by shares | Dissolved |
| GASCOINE LIMITED | Private company limited by shares | Dissolved |
| GASCONTA COMPANY LIMITED | Private company limited by shares | Dissolved |