| WESTPORT COMPANY LIMITED | Private company limited by shares | Dissolved |
| Westport Limited | Private company limited by shares | Live |
| Hong Kong Westport Trading Co., Limited | Private company limited by shares | Live |
| WESTPORT TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| Westport Communications Limited | Private company limited by shares | Dissolved |
| WESTPORT DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| GRAND WESTPORT LIMITED | Private company limited by shares | Live |
| WESTPORT GROUP, LIMITED -THE- | Private company limited by shares | Dissolved |
| Westport Innovations (HK) Holdings Limited | Private company limited by shares | Live |
| Westport Innovations (Hong Kong) Limited | Private company limited by shares | Live |
| WESTPORT TECHNOLOGY (HONGKONG) CO., LIMITED | Private company limited by shares | Live |
| WESTPORT PACIFIC INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| WESTPORT INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| WESTPORT SHIPPING LIMITED | Private company limited by shares | Dissolved |