A Russian businessman seen as close to President Vladimir Putin is about to take a $3.7 billion stake in potash giant Uralkali from billionaire Suleiman Kerimov, the RIA Novosti news agency reported Friday, citing a source. Businessman Vladimir Kogan is reported to be picking up Kerimov\'s 21.7 percent share in the Russian potash producer with another source telling Prime news agency that Kogan has \"already paid the first instalment\" to Kerimov. Kogan is believed to have been friendly with Putin ever since both worked in their native city of Saint Petersburg. After starting out as a car mechanic, Kogan became a banker and moved on to senior positions in the federal building agency and the ministry of regional development. Forbes magazine estimates Kogan\'s fortune at $950 million. Kerimov, the owner of Russian football club Anzhi, is believed to have suffered massive losses after Uralkali made a surprise decision to pull out of a joint venture with Belarus to produce potash, a key component in fertilisers. He has been charged by Belarus of abuse of authority at Uralkali. Uralkali in July pulled out of a joint venture with Belarus\'s giant potash producer Belaruskali, causing the end of a cartel that had kept potash prices high worldwide. Belarus responded by detaining Uralkali\'s chief executive Vladislav Baumgertner at the Minsk airport after he flew in on the invitation of the Belarussian premier. Kerimov is charged with abuse of authority and Belarus has asked Interpol to issue an international arrest warrant for him, a request that has been denied.