Former Allegheny County Councilman Ron Francis has ended his campaign for the GOP nomination to run against U.S. Rep. Jason Altmire, ensuring a rematch this year between Mr. Altmire, and former Rep. Melissa Hart, who lost the seat in 2006.

In a letter to supporters on Thursday, Mr. Francis said he was backing Ms. Hart, of Bradford Woods, to make sure the party is united going into the 2008 election.

"That's going to be required to win," Mr. Francis, a Ben Avon Republican and a partner at the Downtown law firm Reed Smith, said yesterday. "A primary fight was going to only help Altmire."

Mr. Francis and Ms. Hart spoke this week, and she invited him to chair her campaign.

"I was very honored that he agreed to do so," Ms. Hart said. "We have a unified team going into the election. It's a great advantage."

Mr. Francis said he also based his decision on the difficulty of raising money for what would have been a hugely expensive race.

Mr. Altmire, a McCandless Democrat, already has a significant cash advantage. He has raised more than $890,000, according to the Center for Responsive Politics, while Ms. Hart has raised about $239,000 and Mr. Francis has raised about $135,000.

Ms. Hart and Mr. Altmire spent more than $3.2 million in the 2006 race, and Mr. Altmire defeated her, 52 to 48 percent.

Nationally, Democrats captured 30 seats from Republicans and took control of the House.

Mr. Altmire said he always assumed he would be facing Ms. Hart this year.

"[Mr. Francis'] departure doesn't change our strategy," he said.