YUKOS
YUKOS (ЮКОС) is a petroleum company in Russia, controlled by Russian billionaire Mikhail Khodorkovsky and a number of prominent Russian businessmen.Yukos is one of the world's largest non-state oil companies. It was acquired in controversial circumstances from the Russian Government during the privatization process of the early 1990s.
In April 2003, Yukos agreed to a merger with Sibneft, but the merger was soon undone in the aftermath of the arrest of Yukos CEO Khodorkovsky in October, 2003.
The high-profile arrest of Khodorkovsky is widely believed to have been due his activism in the Russian political process. Shortly thereafter, on October 31, the Russian government froze ownership of 44% of the companies shares. The reason given was to prevent them from them being sold by a group of major shareholders led by Khodorkovsky.