The story
Tomskneft is the successor company to a Soviet plant that was founded in January 1966 by the decree of the Tyumen oil and gas industrial enterprise. The plant extracted the first million tons of oil in 1969. By 1974, it produced 25 million tons of oil. In 1977, the Ministry of Oil Industry separated Tomskneft from the Tyumen oil and gas industrial enterprise, thus forming the Tomskneft industrial association.
Following the dissolution of the Soviet Union, Tomskneft was privatized in 1993. The next year, together with the Achinsk oil refinery, the Tomskneftekhim factory, and several smaller Siberian oil companies it formed the basis upon which the newly founded Eastern Oil Company (EOC) was organized.
In 1997, Yukos, one of the largest Russian oil producers at the time, acquired the majority interest of the EOC, thus taking over Tomskneft and the EOC's other subsidiaries. Tomskneft was a part of Yukos until 2007, when its shares were sold to Rosneft and Gazpromneft due to the parent company's bankruptcy. Each company acquired 50% of Tomskneft's stocks.
In August 2021, Rosneft sold its block of Tomskneft's shares to the Independent Oil Company.
From Wikipedia’s article on Tomskneft, shared under CC BY-SA 4.0.4