MOSCOW, June 13 (RIA Novosti) - A quartet of Russian billionaires owning half of oil company TNK-BP issued a statement on Friday on the start of legal proceedings against co-owner BP, condemning 'illegal' steps by the British company.

The statement from Alfa-Access-Renova (AAR) consortium, through which the tycoons hold their shares in the country's third-largest oil company, did not cite specific allegations. The Russians previously said the dispute is over managerial and strategic issues, while BP accuses the tycoons of attempting a corporate raid.

The statement said: "The development of the conflict between shareholders of TNK-BP is being provoked by the unilateral and illegitimate actions of CEO Robert Dudley. AAR consortium is announcing the start of legal procedures to draw up a petition for the courts, to have the illegality of BP representatives' actions recognized."

AAR is owned by billionaires Viktor Vekselberg, Len Blavatnik, and German Khan and Mikhail Fridman of Alfa Group.

The consortium said BP has "consistently ignored" its offers and demands, and that "AAR's options for reaching a compromise have now run out."

Among the complaints leveled against BP, the Russian shareholders say the company has placed too many foreigners in top-management positions, that Robert Dudley has put the interests of BP ahead of TNK-BP, and that AAR has been given insufficient say in strategic decisions.

However, BP Chairman Peter Sutherland said on Thursday: "It is unfortunately a much simpler dispute over control, and perhaps ultimately ownership of the company."

"This is just a return to the corporate raiding activities that were prevalent in Russia in the 1990s."

Sutherland said the Russian leadership is standing by and allowing the tycoons to push forward with their takeover attempt.

"Prime Minister Putin has referred to such tactics as relics of the 1990s, but unfortunately our partners continue to use them, and the leaders of the country seem unwilling or unable to step in and stop them," he said.

The Kremlin has said it does not intend to intervene in the ongoing dispute between Russian and British shareholders.

Analysts have suggested the dispute could result in Russia's third-largest oil company being bought up by state-controlled Gazprom or Rosneft as part of the Kremlin's campaign to toughen its grip on the oil and gas sector.