Democratic Senator Kent Conrad, who has led efforts to get the U.S. budget under control, said Tuesday that he will not run for re-election in 2012, a decision that helps Republican efforts to win control of the Senate after a strong showing in 2010.

Conrad's warnings about the United States' fiscal woes led to a presidential commission that recommended spending caps and a revamped tax code last year in order to head off a Greek-style debt crisis.

The commission's plan could form the basis for deficit-reduction efforts in Congress as lawmakers seek to bring down shortfalls that have reached 9 percent of GDP in recent years.

"It is more important I spend my time and energy trying to solve these problems than to be distracted by a campaign for re-election," the North Dakota Democrat said in a prepared statement.

As chairman of the Senate Budget Committee, Conrad will play a crucial role in the looming battle over federal spending.

Republicans who control the House of Representatives are pushing for deep cuts to domestic programs, but the Democratic-controlled Senate is unlikely to go along. The two chambers will have to agree on a spending plan by March to avoid a government shutdown.

Conrad, 62, has amassed a moderate voting record since he was first elected to the Senate in 1986. He likely would have faced a tough re-election fight in his rural state. Fellow North Dakota Senator Byron Dorgan retired last year ahead of a tough re-election. Republican John Hoeven easily won the seat.

Republicans need to pick up four seats in 2012 to win control of the 100-seat Senate.

The National Republican Senatorial Committee, which is leading that effort, said Conrad's seat is one of their best opportunities.