UPDATE 1-Putin backs BP's sale plan for TNK-BP - FT

(Adds Fridman comment, detail)

LONDON/MOSCOW, Oct 10 (Reuters) - Russian president Vladimir Putin backs BP's plan to sell its 50 percent stake in TNK-BP to state oil group Rosneft , the Financial Times reported on Wednesday, citing an interview with Rosneft Chief Executive Igor Sechin.

Putin, who returned to the Kremlin for a six-year presidential term in May, dominates the country's power hierarchy and investors are watching for a political signal that Rosneft will receive his blessing to buy into TNK-BP.

Such a deal would require formal government approval, however, and some senior officials have opposed the transaction, saying that state business should not further encroach into the world's ninth-largest economy.

Sechin said Putin had endorsed the idea - which could also include BP taking a stake in Rosneft - at a meeting in Russia last month with BP's top executives.

"(Rosneft) will have the opportunity to acquire a strategic investor ... so we do support this, and the president also spoke in support of this," Sechin, a long-standing confidant and adviser to Putin, was quoted as saying.

Sechin said, however, that Putin stressed it was ultimately "up to BP shareholders" to decide on the deal.

"Considering the fact that Rosneft is a strategic company ... the main parameters of the deal have to be agreed with the presidential administration," he said.

BP's four billionaire partners in TNK-BP - Mikhail Fridman, German Khan, Viktor Vekselberg and Len Blavatnik - who initially wanted to buy BP out of the venture, have told the British firm they may instead sell their half of the $50 billion business.

In so doing, the four (who are grouped in a consortium called AAR) signalled their unwillingness to work alongside Rosneft, the listed oil company with the world's top oil resources.

With AAR now putting its own stake up for sale, BP has the right under a shareholder agreement to a 45-day exclusivity period in which AAR may not consider bids from other potential buyers.

Asked on Wednesday whether AAR may sell its stake in TNK-BP before BP does, Fridman told reporters: "Everything is possible".

The divorce is the results of a protracted feud between BP and AAR after the latter blocked BP's attempt to partner with Rosneft last year in the courts.

(Reporting by Stephen Mangan and Polina Devitt; Writing by Vladimir Soldatkin; Editing by David Holmes)

((stephen.mangan@thomsonreuters.com)(+44 0 20 7542 7931))