NEW YORK. Oct 5 (Interfax) - Sergei Karaganov, the head of the Foreign and Defense Policies Council, a Russian think tank, doubts President Vladimir Putin will choose to become prime minister after leaving the presidency.

Putin "of course will remain in power. No doubt about that. He will leave the presidency with tremendous public support. One could expect that he will be back in 2012," Karaganov told an investment conference organized by Troika Dialog in New York on Thursday.

"I do not think that he will become prime minister. If he does he would have to bare responsibility for all possible failures. This is a lot of risk. It is likely that Putin will 'reign but not rule'. It is possible he will hold an influential position in the economic sector," Karaganov said.

Karaganov said he was convinced the fight against corruption will be a priority in Russia's domestic policy. "This will allow to call oligarchs to order, to make them unable to regroup and challenge the authorities as they did ten years ago," Karaganov said.

"(Russian Prime Minister) Viktor Zubkov is an ideal candidate for premier or president. He has much experience in fighting money laundering and he has links with none of the clans. He owes everything to Putin only," the expert said.

Experts are now looking into the two most likely scenarios, German political scientist Alexander Rahr said. "A technical president emerges and Putin becomes a strong premier. The second scenario is collective leadership: Ivanov as a strong president and Putin as a strong premier," Rahr said.