AAR agrees to $28bn TNK-BP deal BP's billionaire partners in TNK-BP have agreed a deal to sell their stake in the troubled Russian oil producer to Russia's national oil champion Rosneft for about $28bn, according to a person familiar with the matter. The outline deal, first reported by Sky News, was agreed in Moscow last night between Rosneft and AAR, the consortium of oligarchs led by Mikhail Fridman who own 50 per cent of TNK-BP. Such a transaction increases the likelihood that Rosneft will end up owning the whole of TNK-BP, or that BP will remain in the joint venture as a partner with the national oil company, people familiar with the matter said. If Rosneft does buy the whole venture, it will become by far the world's largest publicly-listed oil company, with 4.5m barrels a day of production. A person close to BP said it was good news for the company because the figure of $28bn provided a "good price point" for its own stake in TNK-BP. Meanwhile, if it ended up staying in TNK-BP with Rosneft, it would have a strong partnership with Russia's most powerful oil company. BP announced in June that it was pursuing a sale of its half of TNK-BP, after years of corporate disputes between the UK oil group and its Russian partners. The tensions climaxed in the summer of 2008 when Bob Dudley -TNK-BP's then chief executive, and currently BP's chief executive - was forced to leave Russia. Since June, BP has been in talks with both Rosneft and AAR on a deal. Rosneft had discussed a cash-and-shares transaction which would leave BP with a sizeable stake in the state-run Russian oil company. The UK group says it expects formal offers for its stake from tomorrow at 9am, when a 90-period for good-faith negotiations with AAR expires. Under the TNK-BP shareholder agreement, BP can negotiate with other bidders apart from AAR during that period but cannot do a deal with them. AAR could still submit an offer for the BP stake when the 90-day deadline expires, the person familiar with the matter said. The person close to BP said any deal between AAR and Rosneft would not affect its decision to sell its stake in the company. BP's shares were up 3.2 per cent to 449.25p in early trading.