Steve Welch, a wealthy Republican biotechnology entrepreneur, abandoned his bid for the U.S. House yesterday in a surprise announcement at the Chester County GOP's nominating convention in Kennett Square.

Welch, 33, whose chances at securing the full backing of the GOP all but evaporated when Rep. Jim Gerlach decided in January to run for reelection, said it was time to unify behind Gerlach.

"At this point I would be doing more damage than good to the values I hold dear," Welch said in a phone interview yesterday.

Welch began campaigning last fall in the Sixth District, which includes parts of Chester, Montgomery, Berks, and Lehigh Counties, after abandoning a short run in the neighboring Seventh District, where he lived.

The party establishment in the Seventh District, which includes most of Delaware County and slivers of Montgomery and Chester Counties, backed former U.S. Attorney Pat Meehan for the seat. So Welch switched his campaign to the Sixth District, moving into a home squarely within it.

At the time, his chances looked good, and he spent $650,000 of his own money to bulk up his campaign funding. Gerlach left the governor's race in January, and party leaders in Montgomery County and Washington quickly backed him. But Welch vowed to stay in, hoping to garner some support in Chester and Berks Counties.

Welch said yesterday that he could not shore up the support he needed to justify continuing.

He said that he would run again, but that he didn't know if he would run as soon as 2012. "I have enjoyed the campaign process greatly, even though I had some bad luck," he said, laughing.

Welch left no doubt about whom he supports for the seat. "I am supporting Jim Gerlach," adding that the incumbent was in "the best position" to win the seat for the Republicans.