|Date||Main Developments in the Company's Business|
|1893||Vacuum Oil (U.S.) Japan branch
Socony (U.S.) Japan branch
|1932||Socony-Vacuum (U.S.) Japan branch|
|1934||Stanvac (U.S.) Japan branch|
|1939||Toa Nenryo Kogyo K.K. (changed to Tonen K.K. in 1989)
Toa Nenryo Kogyo was founded jointly by eight Japanese petroleum companies to produce aviation gasoline and lubricants.
|1947||General Bussan K.K.
With the dissolution of "zaibatsu" groups in Japan, the fuel division of MITSUI & CO., LTD. became independent as General Bussan (later General Sekiyu K.K.) and was certified as a "motouri".
|1949||Partnership between Toa Nenryo Kogyo and Stanvac
Toa Nenryo Kogyo formed a partnership with Stanvac to introduce Standard Oil technology. Stanvac acquired 51% of Toa's shares (later reduced to 50%).
|1958||General Sekiyu K.K.|
|1960||Tonen Sekiyu Kagaku (now Tonen Chemical Corporation)|
|1961||Mobil Sekiyu K.K.
Esso Standard Sekiyu K.K.
Mobil Sekiyu and Esso Sekiyu established with the dissolution of Stanvac.
Mitsui Oil Supply Company, Limited
Established as a wholly owned subsidiary of MITSUI & CO., LTD.
Nitto Unicar Company Limited
Established as a joint company of Nitto Chemical Industry Co., Ltd. and Union Carbide Corporation (currently Dow Chemical).
|1963||Kyokuto Petroleum Industries K.K. (now Kyokuto Petroleum Industries, Ltd.)
Mobil Sekiyu and MITSUI OIL invested equally in the establishment of Kyokuto Petroleum Industries, a petroleum refining specialist.
Nippon Unicar Company Limited
|1980||Tonen Sekiyu Kagaku (currently Tonen Chemical Corporation) became the Japanese shareholder in 1980.|
|1982||Esso Sekiyu K.K.|
|1990||MITSUI OIL CO., LTD.|
|2000||TonenGeneral Sekiyu K.K.
Tonen and General Sekiyu merged to become TonenGeneral Sekiyu.
|2002||ExxonMobil Yugen Kaisha
With the merger of U.S. companies Exxon and Mobil in 1999, the Japanese companies they had invested in were also restructured.
|2012||EMG Marketing Godo Kaisha
Integrated management as the TonenGeneral Group with TonenGeneral Sekiyu's acquisition of 99% of EMG Marketing shares in June, making EMG Marketing a TonenGeneral Sekiyu subsidiary.
Nippon Unicar Limited became a wholly owned subsidiary of TonenGeneral Sekiyu and was renamed NUC Corporation with the acquisition of shares owned by Dow Chemical.
|2014||MOC Marketing Godo Kaisha
Sales business of MOC Marketing transferred to and integrated with EMG Marketing in July.
MITSUI OIL shares transferred to TonenGeneral Sekiyu under agreement by TonenGeneral Sekiyu and MITSUI & CO., LTD. MITSUI OIL and Kyokuto Petroleum Industries became subsidiaries of TonenGeneral Sekiyu in February.
|2015||Kyokuto Petroleum Industries acquired by TonenGeneral Sekiyu through an absorption-type merger in July.|
|2016||TonenGeneral Sekiyu executed a business integration agreement and other agreements with JX Holdings, Inc., in August.|
|2017||EMG Marketing acquired by TonenGeneral Sekiyu through an absorption-type merger in January.|