* BP lawyer says no legal grounds for joining the lawsuitBy Vladimir SoldatkinMOSCOW, Oct 18 (Reuters) - Oil company BP’s 50 percent-owned Russian affiliate TNK-BP will find itself fighting its British parent in court for billions of dollars in compensation if a board decision next week goes the way of the other main shareholders.BP and the quartet of billionaires who hold the other half of Russia’s third largest oil producer have clashed over BP’s attempt to open up a new Russian investment stream and strike a new exploration and share swap deal with state-controlled Rosneft.Through their Alfa-Access-Renova (AAR) consortium, the group of Russian businessmen successfully blocked the Rosneft deal in May. Rosneft has since turned to U.S. based Exxon as a replacement partner.Now minority shareholders in the listed subsidiary of 50-50 joint venture TNK-BP Ltd, TNK-BP Holding, are seeking damages of over $13 billion in a Russian regional court from BP and two BP nominees on the board of TNK-BP Holding, Peter Charow and Richard Sloan. TNK-BP Ltd controls 96.5 percent of TNK-BP Holding. The rest is in free float.A BP spokesman in Moscow said “there is no merit to the lawsuits against directors since there were in fact no damages in the form of lost profits.”AAR has said it has no connection with the suit brought by the TNK-BP minority shareholders. But sources close to the consortium representing four tycoons — Mikhail Fridman, German Khan, Viktor Vekselberg and Len Blavatnik — have said they are sympathetic to the action.AAR had no immediate comment.BACKING THE LAWSUITDirectors have put forward a motion to be discussed on Oct. 24 that the company should back the lawsuit, a TNK-BP spokesman said on Tuesday.”At the request of one of the TNK-BP Holding (THB) directors, on Oct. 24 the Board of Directors of TBH will consider the question of whether or not to join the lawsuit being put forward by one of its minority shareholders,” the spokesman said.TNK-BP Holding has a nine-member board — with four each for BP and AAR. The sole independent director, David Lasfargue, would have an effective casting vote on whether to pursue the action.”The prerogative of deciding TBH participation in these legal proceedings lies within the exclusive jurisdiction of the Board of Directors of TNK-BP Holding and does not involve participation of the company’s management,” the TNK-BP spokesman said.Reached in Paris by telephone, Lasfargue declined to comment on the case.In the lawsuit, filed in the West Siberian town of Tyumen, TNK-BP’s base, Prokhorov claims TNK-BP suffered damages because BP decided not to act via its existing Russian joint venture in the Rosneft deal, in violation of an exclusivity clause in the TNK-BP shareholder agreement.There is a potential snag facing the case of plaintiff, Andrey Prokhorov.Konstantin Lukoyanov, a lawyer for BP, said a Russian judge had refused Prokhorov more time to attract other investors to his case. He holds less than 1 percent and needs to get over the 1 percent threshold in order to legally file a lawsuit in such cases.”As of today, TNK-BP Holding has no legal right to join the minority shareholders lawsuit,” Lukoyanov said.