Oligarchs Assemble Team for Oil Deals LONDON - They were once the partners of the British oil giant BP, until that arrangement spun apart in turmoil and litigation. Now the Russian billionaires Mikhail Fridman and German Khan want to go back into the global energy market, investing much of the $14 billion they received when they sold their piece of that partnership this year. And in case Westerners might worry about doing business with Mr. Fridman and Mr. Khan, given their tempestuous history with BP, they have surrounded themselves with some highly regarded global executives - including the former chief executive of BP. John Browne, that former BP chief, is among the paid advisers recruited to the new Fridman-Khan investment fund, L1 Energy, which intends to acquire oil and natural gas properties in North America and emerging markets. Also adding industry credibility are James T. Hackett, former chief of the American exploration company Anadarko Petroleum, and Andrew Gould, onetime head of the oil services giant Schlumberger and now chairman of BG, the oil and gas producer. Will those prestigious advisers be enough to reassure potential partners that it is safe to do business with oligarchs? Mr. Hackett and Mr. Browne did not return calls seeking comment. In a telephone interview, Mr. Gould said the Russian executives" history of litigation was "a cause for reflection," but he added, "I don't think you should take the past as a guide for the future." That past might be best forgotten if it wasn't so colorful. In 2008, after Mr. Browne's departure from BP, bickering over the management of the Russian partnership, known as TNK-BP, led the Russians to demand the resignation of the BP-appointed chief executive of TNK-BP, Robert W. Dudley. Eventually, Mr. Dudley left Russia after the partners maneuvered to have his visa revoked, according to BP. Things reached such a pitch that Mr. Dudley said he felt it necessary to work for a time in hiding outside Russia. Warring broke out again in 2011 after Mr. Dudley became chief executive of BP and concluded an Arctic exploration deal with the Russian state-owned oil giant Rosneft, a rival to the oligarchs in TNK-BP. They successfully blocked that Rosneft pact through legal action in London. During that struggle, a Russian minority shareholder in the partnership filed a $16 billion lawsuit in Siberia against BP and some of its executives, seeking damages from the Rosneft deal. The claim became the basis for a raid on BP's office in Moscow that year by police officers armed with assault rifles. The suit melted away as soon as BP and the Russian partners in TNK-BP agreed in late 2012 to sell the company to Rosneft, a deal that closed early this year. And somewhere along the way, according to a WikiLeaks document from the United States Embassy in Moscow, a former TNK-BP executive described to an American diplomat how Mr. Khan had shown up for dinner at a remote hunting lodge with a chrome-plated pistol and confided to the executive that he considered the 1972 film "The Godfather" a "manual for life." A spokesman for Mr. Khan did not respond to a query about the episode. Representatives for Mr. Khan and Mr. Fridman said neither executive was available for interviews. Given their past, the Russian billionaires "will have to legitimize their company by bringing in prominent names," said Fadel Gheit, an oil analyst at Oppenheimer & Company in New York. They will have to recruit an all-star team. Mr. Fridman and Mr. Khan are longtime friends and among the founders of an investment firm, the Alfa Group, that also has banking and telecommunications interests. As with many of Russia's current generation of billionaires, the two made their fortunes by being well placed to capitalize during the sell-off of state-owned assets in the early 1990s. Their main trophy was a company called Tyumen Oil. The two have done very well since, accruing estimated wealth of $16.5 billion for Mr. Fridman and $10.5 billion for Mr. Khan, according to Forbes. Mr. Fridman is the dominant figure in the partnership and the strategic thinker, associates say, while Mr. Khan has been the point man for oil investments. They plan to funnel as much as $10 billion of their fortunes into oil and gas deals. With borrowed cash, they plan to leverage their money into a $20 billion war chest. The energy investments will be part of a broader effort to diversify the Alfa Group outside Russia and, possibly, create a publicly listed company, according to a person close to the planning. Such diversification is a natural move for Russian oligarchs and other top business figures in emerging markets who want some of their golden eggs kept outside home-country baskets. L1 Energy, which will be run by Mr. Khan from London, aims to make a few large investments over the next few years, working with existing management at the target companies or installing new executives as it sees fit. "We are not interested in just having a seat on the board - we want to be in a position to influence a company," Stan Polovets, the lead member of the advisory board, said in an interview at the Berkeley Hotel in London. He is the one lining up L1 Energy's outside advisory board. "Alfa shareholders know well how to be successful in the former Soviet Union; that doesn't necessarily translate into success when they step outside in such a major way," said Mr. Polovets, who was previously the chief executive of Alfa-Access-Renova, the vehicle for the Russian holdings in TNK-BP. Mr. Polovets says that L1 Energy's crucial investment strengths will include comfort with emerging-market risks and the ability to make decisions quickly. It was Mr. Browne, the first of the advisers Mr. Polovets recruited to L1 Energy, who presided over the creation of the TNK-BP partnership with the Russian billionaires in 2003, by combining BP's Russian assets with the men's Tyumen Oil. BP made more than five times its original $8 billion investment through dividends and the cash and share sale of TNK-BP to Rosneft last year. But the repeated bouts of quarreling with the Russian partners sapped management time and alarmed BP shareholders. Mr. Gould, whose former employer, Schlumberger, played a vital role in reviving the Russian oil industry after the fall of the Soviet Union, said he had joined the L1 Energy advisory board "because it's a group of people I know well; it is fun to be together." He said that the group "had a vast amount of experience" in the oil and gas industry and "can provide quality advice on the deals the fund may be contemplating." The question is whether Mr. Fridman and Mr. Khan will be able to thrive outside Russia. A Western executive, who knows Mr. Khan and spoke on the condition of anonymity because he does not want to risk business relationships, said the Russian partners understood the oil business. But he wondered whether they would be able to make big money outside their home country and away from "the kangaroo Siberian courts." "They will be surprised," he said, "when they look at the returns they get playing by real rules." Stanley Reed reported from London and Andrew E. Kramer from Moscow.