U.S. Republican presidential hopeful Newt Gingrich is planning to suspend his campaign, according to media reports Wednesday.

File photo of U.S. Republican presidential hopeful Newt Gingrich

Fox News quoted senior campaign aides as saying Gingrich planned to formally pull out of the GOP presidential race next Tuesday and would likely endorse presumed nominee Mitt Romney when he makes his announcement.

The report indicated the decision came after Gingrich talked with advisers after Romney won five primaries Tuesday night. The victories make it virtually impossible for Gingrich to secure the 1,144 delegates needed for the Republican nomination.

Despite stints on top of national polls, Gingrich has only won contests in South Carolina and Georgia and, according to a CNN count, he only has some 141 delegates to his name.