| QUARK LIMITED | Private company limited by shares | Dissolved |
| Top Quark Limited | Private company limited by shares | Live |
| Quark Limited | Private company limited by shares | Live |
| X&Y Quark Limited | Private company limited by shares | Live |
| QUARKIE LIMITED | Private company limited by shares | Live |
| Quarkon Limited | | Live |
| QUARKS CO. LIMITED | Private company limited by shares | Live |
| Quarks Limited | | Live |
| Quarks Capital Limited | Private company limited by shares | Live |
| QUARKS GROUP LIMITED | Private company limited by shares | Dissolved |
| Three Quarks Limited | | Live |