LONDON (BLOOMBERG) - Mr Vladimir Potanin, Russia's second-richest man, is facing one of the world's biggest divorce claims after Mr Jeff Bezos and Mr Bill Gates. His former wife, Ms Natalia Potanina, is seeking 50 per cent of the value of his stake in MMC Norilsk Nickel PJSC, outlining the maximum amount at a London court hearing on Tuesday (Dec 7).

That amount could exceed US$7 billion (S$9.6 billion), given that Mr Potanin owns around one-third of the shares in the metal producer. Mr Potanin is fighting the case after Ms Potanina overturned a lower court that accused her of "divorce tourism".

Mr Potanin is still waiting to hear whether the British Supreme Court will consider an appeal, Judge Nicholas Francis said. London's divorce courts have been a popular destination for high-value legal fights, with judges typically prepared to order a more equal share of a couple's assets.

In Britain, the largest publicly known payout in a divorce is currently £450 million (S$813 million) to the wife of billionaire Farkhad Akhmedov - though the two settled with a payment of less than one-third of that amount.

Ms Potanina said that in addition to the Norilsk stock, she would be prepared to accept 50 per cent of all dividends on the shares from 2014. Her former husband has collected some 487.3 billion rubles (S$9 billion) in dividends since then and has a net worth of US$29.9 billion, according to the Bloomberg Billionaires Index.

Ms Potanina is also seeking half of the value of an expensive Russian property known as the Autumn House.

She said she received around US$40 million following Russian divorce proceedings while Mr Potanin said she ended up with US$84 million - a sum that by English standards is a "paltry award", given the his wealth and the length of their 31-year marriage, a judge said in a previous decision.

Ms Frances Hughes, a lawyer for Ms Potanina, declined to comment. A lawyer for Mr Potanin did not immediately return e-mails seeking comment.