Viktor Vekselberg, 51

Head of Renova Group, an $18 billion management company with interests in oil, metals and mining, electricity, media, construction, chemicals and finance. A former engineer in Communist times, he plotted Russia’s first successful hostile takeover in 1994, of the Vladimir Tractor Factory. Kept in the Kremlin’s good books by spending a rumoured $100 million to buy nine Faberge imperial eggs from the Forbes family and return them to Russia. Estimated to be worth $11.2 billion

Mikhail Fridman, 44

Chairman and principal founder of Alfa Group, one of Russia’s largest privately owned corporations with interests in banking, insurance, oil and gas, retailing, media and mobile telecommunications. He and Vekselberg sold half of their Tyumen Oil Company (TNK) to BP for $6.75 billion in 2003, then Russia’s biggest single foreign investment. Mr Fridman is Russia’s fourth-richest man, with $20.8 billion, according to Forbes. He was one of the "Big Seven" oligarchs who bankrolled Boris Yeltsin's 1996 re-election against a resurgent Communist Party in return for control of state assets worth billions of pounds. Retains close links to the Kremlin.

German Khan, 46

Former classmate of Fridman at the Moscow Institute of Steel and Alloys. After graduating, they founded Alfa-Eco, a commodities trading group that was a forerunner of Alfa Group. Said to be worth $13.9 billion, he is responsible for Alfa's oil businesses and executive director at TNK-BP. Like Fridman and Vekselberg, he was born in Ukraine.

Len Blavatnik, 50

Grew up in Russia but emigrated to the US in 1978 and is an American citizen. He and his university friend Vekselberg formed Renova in 1990 and created SUAL, which was merged with Oleg Deripaska's RusAl in 2007 to become the world’s largest aluminium company. His US-based holding, Access Industries, acquired a stake in TNK in 1997 and forms part of the Access-Alfa-Renova group that retains 50 per cent of TNK-BP. Estimated wealth of $8 billion.

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