| Abu Dhabi Oil Co., Ltd | .Maruzen Oil Co., Ltd. |
| Castrol | Mitsui Oil And Gas Co., Ltd. |
| Corning | Mobilsekiyu Kabushiki Kaisha |
| Cosmo Oil Co., Ltd | Nichigo Engineering |
| Esso Sekiyu K. K. | Nippon Mitsubishi Oil Corporation |
|
Exxonmobil |
Okinawa Sekiyu Seisei Company, Ltd. |
| Fuji Kosan Co., Ltd. | Seibu Oil Co., Ltd. |
| General Sekiyu K. K. | Showa Shell Sekiyu K.K. |
| Idemitsu Kosan Co., Ltd. | Showa Yokkaichi Co. |
| Inpex Corporation | Taiyo Oil Co., Ltd. |
| Japan Drilling Co., Ltd. | Teikoku Oil Co., Ltd. |
| Japan Energy Co., Ltd. | Toa Oil Co., Ltd. |
| Japan Oil Development Co., Ltd. | Tonen Corporation |
|
Koa Oil Co., Ltd. |
UNOCAL(加州石油) |
| Kyushu Oil Company Limited | Yushiro Chemical Industry Co., Ltd |