Exxon Neftegas Limited, a subsidiary of U.S.-based Exxon Mobil Corporation, is the operator of the Sakhalin-1 Project and holds a 30% interest.

Sakhalin Oil and Gas Development Co., Ltd. is a Japanese investment company (whose principal shareholders are JNOC, JAPEX, Itochu and Marubeni) and holds a 30% interest.

ONGC Videsh Limited, a subsidiary of Indian National Oil Company ONGC, is based in India and holds a 20% interest.

Sakhalinmorneftegas-Shelf, a subsidiary of Rosneft-Sakhalinmorneftegas, is a Russian Company and holds an 11.5% interest.

RN-Astra, a subsidiary of Russian national oil company Rosneft, is a Russian company and holds an 8.5% interest.