Legal move looms after 'harassed' TNK-BP boss leaves Russia

BP is poised to launch legal action against the four Russian billionaires who own half of TNK-BP, as the battle for control of the joint venture continues to escalate.

News of the likely legal move comes after the UK Foreign and Commonwealth Office warned that the departure of TNK-BP's chief executive, Robert Dudley, was detrimental to both the Russian and British economies and to the global energy industry.

Mr Dudley, a US citizen, left Russia on Thursday due to what BP called a campaign of "sustained harassment" by TNK-BP's co-owners, Alfa, Access and Renova (AAR). AAR is owned by the Russian oligarchs Mikhail Fridman, German Khan, Viktor Vekselberg and Len Blavatnik.

BP said Mr Dudley had faced underhand tactics and unprecedented investigations – including being questioned by the interior ministry over alleged corporate tax evasion. "His ability to carry out his job was being severely interfered with," said a BP spokesman.

Mr Dudley will continue to run the company from an undisclosed location. But his departure means AAR will have greater control of the 50:50 venture and is the latest chapter in the rise of nationalism that is shutting Western oil companies out of energy- rich regions of Russia.

A Foreign Office spokesman said: "The way shareholders have manipulated elements of the Russian state bureaucracy and the way this has been allowed to continue is very disappointing. The Prime Minister raised the issue with President Medvedev during the G8, and both agreed on the importance of a resolution according to the rule of law."

Chief executive Tony Hayward said that BP will use all means at its disposal "both inside and outside of Russia" to defend its interests and rights. A spokesman added that legal action was the most likely route. Under the TNK-BP shareholders' agreement, either BP or AAR can launch proceedings at Stockholm's international arbitration court.

The oligarchs deny harassment and claim they are trying to have Mr Dudley removed from office because they believe he favours BP and that he has caused the company to underperform. Mr Hayward rejected both claims, adding that TNK-BP's performance has been "stellar".

BP's stake in TNK-BP, Russia's third-largest oil producer, provides about a quarter of its total output and a fifth of proven reserves.