Russian prosecutors requested Tuesday that Mikhail Khodorkovsky, the former chief executive of the Yukos oil company, be sentenced to 10 years in a prison labor camp.
Chief Prosecutor Dmitry Shokhin asked a Moscow court to find Khodorkovsky guilty on tax evasion and other charges.
Khodorkovsky and his business partner, Platon Lebedev, have been the target of a lengthy court process stemming from the allegedly illegal acquisition of shares in a fertilizer-component maker in 1994.
Khodorkovsky has repeatedly denied that he is guilty of any charges and noted that under the law of the time, the deals were not illegal.
The criminal case against Khodorkovsky and a parallel tax case against Yukos have reduced the company - once Russia's largest oil producer - to a shell of its former self.
President Vladimir Putin has repeatedly contended that both investigations targeted a rotten business empire and its owners.