WASHINGTON (Reuters) – Former U.S. Republican presidential nominee will endorse Marco Rubio in the race for the party’s presidential nomination, Huffington Post reported on Sunday.

The endorsement came on the heels of Rubio’s second-place finish in Saturday night’s primary in South Carolina, where he edged out rival Ted Cruz for the No. 2 slot, the website reported, citing unidentified Republican sources.

Romney will join a list of so-called establishment endorsements to back the first-term U.S. senator from Florida, including South Carolina Governor Nikki Haley, who endorsed Rubio days before the state’s primary.

(Reporting by Alana Wise; Editing by Doina Chiacu)

Photo: Former Republican presidential candidate Mitt Romney gestures as he speaks at the Republican National Committee Winter Meeting in San Diego, California January 16, 2015. REUTERS/Mike Blake