Jon Huntsman Jr. will end his bid for the presidency Monday and endorse GOP rival Mitt Romney, a campaign source confirms.
The decision by the former Utah governor follows his third-place finish in the New Hampshire primary last Tuesday.
Huntsman had staked his political future on the primary, and the disappointing result failed to provide his campaign with the momentum and financial resources it needed to carry on to contests in South Carolina and Florida.
Huntsman had just won the endorsement Sunday of the Columbia State newspaper in South Carolina. But polls showed him trailing the other five Republican hopefuls ahead of Saturday's primary in South Carolina.
Huntsman will make a formal announcement about his plans Monday in Myrtle Beach, S.C., where he had been scheduled to deliver a speech on the "broken politics" of Washington.
Paul West contributed to this report.