The state's Republican Party endorsed Mitt Romney's bid for governor Saturday but rejected the Salt Lake City Olympic chief's choice for lieutenant governor.

Romney, the son of a former Michigan governor, pledged to apply the same efficiency and managerial common sense to running state government that he used to oversee the Winter Olympics.

"With a message of change and reform and the resolve I know is necessary to lead this state to its fullest potential, I proudly accept your nomination for governor," he said.

Romney returned to Massachusetts riding a wave of Olympic glory and forced an incumbent governor, Jane Swift, and her hand-picked running mate, Patrick Guerriero, to drop out of the race.

Romney chose Kerry Murphy Healey, the state party chairwoman, as his running mate. But even Romney's popularity was not enough to help Healey at Saturday's party convention, where about 2,700 Republican delegates favored former party chairman James Rappaport by a 55 percent to 45 percent margin.

Rappaport, a millionaire real estate developer, said the vote showed Republicans believe he is more capable of leading the state if something happened to the governor.

"We want the lieutenant governor to be able to step up to the plate," said Rappaport, who pledged to support Romney.

Romney said he was "thrilled" by the outcome. His nomination on Saturday was capped by a shower of red, white and blue confetti and balloons.

On Saturday, Swift urged Republicans to support Romney. She pledged to campaign for the Romney-Healey ticket in coming months, but left to spend time with her family before Romney got up to speak.