A Moscow court postponed to next week a ruling on a move to take control of Bashneft, an oil company, from tycoon Vladimir Yevtushenkov.
The judge said on October 23 that the next hearing will take place on October 30 after the prosecution requested more time to prepare its case.
Prosecutors filed the suit in September to regain state ownership of Bashneft, citing alleged violations in the privatization and subsequent sale of the company to AFK Sistema investment group.
Yevtushenkov, the main shareholder of the conglomerate, is under house arrest on suspicion of money laundering during the firm's acquisition in 2009.
Yevtushenkov, 66, was arrested on September 16.
He is ranked Russia's 15th richest man by U.S. magazine "Forbes," with an estimated fortune of $9 billion.