| Arabian Oil Company, Ltd. |
Mitsui Oil Exploration Co. |
| Hohsui Corporation |
Nichiro Corporation |
| Japex |
Nippon Oil Exploration Co. |
| Kanzaki Forestry Co., Ltd. |
Nippon Suisan Kaisha, Ltd. |
| Kawatetsu Mining Co., Ltd. |
Nittetsu Mining Co., Ltd. |
| Kyokuyo Co., Ltd. |
Takata Corporation |
| Maruha Corporation |
Tokai Kogyo Co., Ltd. |
| Mindeco |
Tsujino&.Co., Ltd. |
| Mitsui Mining Co.，Ltd. |
|