Putin solves Kremlin riddle: stay on in power

By Guy Faulconbridge

MOSCOW (Reuters) - President Vladimir Putin appears to have solved a riddle that has puzzled Kremlin watchers and investors alike: how will Putin keep power without office?

Putin's answer seems to be: stay in office -- but this time as the most influential member of parliament's biggest party, and even as prime minister.

He told a congress of the United Russia party on Monday that he could be a future prime minister and that he would head the party's list in December parliamentary elections.

Kremlin officials, ministers, deputies and members of United Russia roared with applause and gave a Putin a standing ovation.

Investors and politicians said Putin has unveiled a plan that suggested he would be the real power behind the Kremlin after 2008 while a new president would take a secondary role.

"Putin will be in effect the head of state, it will be just as prime minister," said Ian Hague, partner at New York-based Firebird Management, which has $3.5 billion (1.71 billion pounds) invested in emerging markets, including $1 billion in Russia.

"The presidency would then be a lot less meaningful," Hague said. "The market will like it -- the market likes whatever Putin does."

Putin has brought political stability and presided over nearly eight years of economic growth, a contrast to the chaos which accompanied the 1991 collapse of the Soviet Union.