Prosecutors have asked a Moscow court to sentence the former chief of Russia's giant Yukos oil firm, Mikhail Khodorkovsky, to 10 years in prison on charges of tax evasion and fraud.

Chief prosecutor Dmitry Shokhin sought the maximum 10-year sentence for Mr. Khodorkovsky and his co-defendant, Platon Lebedev. The two men face charges stemming from the 1994 privatization of a fertilizer company, but deny any wrongdoing.

Also, the Rosneft oil firm that acquired Yukos' main production unit at a court-ordered auction last year is suing Yukos for two billion dollars that it says are owed for oil shipments.

Critics call the moves against Yukos Kremlin efforts to dismantle the company and retaliate for Mr. Khodorkovsky's support of the political opposition.

The Kremlin says it is cracking down on corporate crime, including the payment some 28 billion dollars it says Yukos owes in back taxes.

Some information for this report provided by AP, AFP and Reuters.