Jon Huntsman will drop out of the Republican presidential nominating contest on Monday and throw his support behind Mitt Romney, the AP reported.

Huntsman will make his announcement during an event in South Carolina on Monday morning, according to campaign officials who spoke on condition of anonymity.

The 51-year-old former governor of Utah placed third last week in New Hampshire behind first place finisher Romney and Texas Rep. Ron Paul.

Huntsman, who has struggled to remain a viable candidate, is considered the gay friendliest candidate among the GOP field's six strongest contenders.

Former New Mexico Governor Gary Johnson strongly endorsed gay marriage shortly before he switched party affiliation from the GOP to the Libertarian Party, whose presidential nomination he is now seeking. Fred Karger is the only GOP presidential candidate in favor of gay marriage, but his low polling numbers have locked him out of all Republican debates.

Huntsman has spoken in favor of civil unions for gay and lesbian couples and a state's right to decide on the issue of marriage equality.