Moscow - A Moscow court Tuesday refused to dismiss new charges of embezzlement and fraud against former oil tycoon Mikhail Khodorkovsky, Russian news agencies reported.

District Court Judge Viktor Danilkin rejected defence's request that the case be thrown out, and set March 31 for the first trial hearings against Khodorkovsky and his business partner Platon Lebedev.

Prosecutors say the two defrauded investors in their oil major Yukos out of 890 billion rubles (25 billion dollars).

Once Russia's richest man, Khodorkovsky, 45, was imprisoned in 2005 and is serving an eight-year sentence for fraud and tax evasion in 2005. The new charges could extend his term by over 20 years, the defence has said.

Many commentators see the case as a Kremlin coup to regain control over the lucrative energy sector and sideline Khodorkovsky as a potential political opponent.