MOSCOW - Russian Prime Minister and President-elect Vladimir Putin said Tuesday that he would quit as chairman of the United Russia party and nominated outgoing President Dmitry Medvedev as its new leader.

"After my inauguration on May 7, I believe it is right to step down as the leader of the United Russia party," Putin said.

He said that although the Russian constitution does not prohibit the president from being a party member, the spirit is that the president is a consolidating figure for all political forces and for all citizens.

Backing Medvedev as his successor, Putin called on party officials to hold congress in the second half of May to decide the new leadership.

"As Medvedev led the party's list during the State Duma election and since I will offer his candidacy for the post of prime minister, I consider it would be appropriate for him to lead the party, too," Putin said.

Boris Glyzlov, chairman of the ruling party's supreme council, said there would be no doubt that Medvedev would be unanimously elected as the new leader.

"Your proposal will be supported by the entire party," Glyzlov told Putin.

Founded in 2001, United Russia is the dominant party in the country with more than 2 million members. Putin, the most influential political figure in Russia, has been its leader since May 2008.

The party gained 238 out of a total of 450 seats in the State Duma election in December 2011, a much-reduced majority.