| S.T.T. TOURS LIMITED | Private company limited by shares | Dissolved |
| ST-Tex Limited | Private company limited by shares | Live |
| STTM Limited | Private company limited by shares | Dissolved |
| Hongkong S.T.T.M Trading Limited | Private company limited by shares | Live |
| ST.TOPEZ LIMITED | Private company limited by shares | Live |
| HK NEW STTRADING LIMITED | Private company limited by shares | Live |
| Sttradingco Industrial Products Co., Limited | Private company limited by shares | Live |
| ST-TRONIC LIMITED | Private company limited by shares | Dissolved |
| STTRONICS LIMITED | Private company limited by shares | Live |
| STTS LIMITED | | Live |