Scarred by the aluminium wars, Oleg the oligarch steels himself for a new battle

He's gone from Siberia to Belgravia, but now Russia's second-richest man faces a $300m lawsuit over a joint venture that turned sour

Russia's second-richest man, Oleg Deripaska, is being sued for $300m (£156m) by Britain's billionaire Reuben brothers over a disputed aluminium trading venture, The Independent on Sunday has learnt.

The long-running dispute will revive fading memories of Russia's bitterly fought "aluminium wars", at a time when Mr Deripaska, who is partially based in London, is seeking legitimacy in Britain and an eventual Stock Exchange listing for his giant RusAl aluminium corporation.

The claimant Trans-World Metals - a business formed by David and Simon Reuben and their former Russian business partner, Lev Chernoi - last week requested jurisdiction in a British Virgin Islands (BVI) court to sue Mr Deripaska and his associates for allegedly breaking a joint-venture agreement and illegally diverting assets. Trans-World's claim for lost profits, damages, interest and costs totals $300m.

The dispute dates back to an aluminium trading business venture formed in 1995 in the heady days of Russia's privatisation process. At that time the Reuben brothers, ex-scrap-metal traders who had their own meteoric rise, allegedly brought in the young Mr Deripaska as an agent to buy up shares in the privatisations of Russia's giant Bratsk and Sayansk smelters. But Mr Deripaska rapidly grew powerful in his own right and soon was strong enough to join a 50/50 partnership with Trans-World in an Irish-registered aluminium company Tradalco, which operated "tolling" companies trading at huge profits.

According to the claim, by January 1998 Mr Deripaska "wrongly repudiated" the joint venture with Trans-World - with immediate effect.

The claimants alleged that they subsequently discovered that Mr Deripaska and his associates had diverted assets illegally into "shadow" companies - Alucor Trading SA and Sayana Foil SA - that replicated the BVI companies already operating for Tradalco in the Bahamas. These "mirror" companies, set up without Trans-World's knowledge, had the same names but different registrations and bank accounts. According to the claim document, these companies were "used as part of an unlawful scheme wrongfully to divert joint venture assets".

Since 2000 the Reubens have extricated their business from Russia and now maintain a mere 1 per cent share in the Bratsk smelter. The brothers, said to be worth £2.2bn, instead turned their attentions to high-profile UK property acquisitions such as the Millbank Tower.

Mr Deripaska's lawyers maintain that Tradalco was a jointly owned company and not the outcome of a joint venture agreement. Trans-World admits that the alleged joint venture was agreed orally, but lawyers for Mr Deripaska point out that if there had been a joint-venture agreement, it would have been in writing.

Mr Deripaska's lawyer, Paul Hauser, denied that assets had been diverted, and claimed that Tradalco's assets - currently in provisional liquidation in Ireland - have been "fully accounted for" by liquidators PricewaterhouseCoopers. He claimed that Trans-World was unhappy with the outcome of the case in Ireland and launched another case in the BVI. "It is a case of forum shopping," said Mr Hauser.

If the case goes to a full hearing it could prove an uncomfortable ride for Mr Deripaska, given what it may reveal about his meteoric but turbulent rise to riches.

Like his close friend and ex-business partner Roman Abramovich, Mr Deripaska has sought strong British ties, and is thought to be seeking respectability in English society and a possible haven from Russia's political vicissitudes.

His Anglophile credentials are already good. Mr Deripaska is believed to "weekend" regularly in London, to improve his English. In 2003, the billionaire sponsored the lavish Art of Chess exhibition held at Somerset House, featuring beautiful Fabergé chess sets. His wife, Polina, a member of the Yeltsin clan, was educated at Millfield school in Somerset. Mr and Mrs Deripaska recently bought a £25m grade-I Regency house in Belgravia.