Popular U.S. comedians Jimmy Kimmel and Sarah Silverman have broken off their five-year romance, publicists for both said on Monday, ending a relationship that provided fertile ground for outrageous humour.

Kimmel, 40, is host of the late-night ABC television talk show "Jimmy Kimmel Live!", and Silverman, 37, has her own comedy show, "The Sarah Silverman Program," on the cable TV network Comedy Central.

Earlier this year, Silverman performed a duet with actor Matt Damon on Kimmel's program in which she made a mock announcement to her boyfriend that she was cheating on him with Damon, the handsome star of the Jason Bourne spy movies.

Kimmel responded with his own sketch pretending to be in a gay relationship with Damon's good friend, actor Ben Affleck, another of Hollywood's rugged leading men.

The title of Silverman's film of her stand-up comedy act, "Sarah Silverman: Jesus is Magic," was inspired by her relationship with Kimmel.

Silverman, who is Jewish, says in the film that if she had a child with Kimmel, who is Catholic, the couple would have to explain that she is "one of the chosen people" and Kimmel believes that "Jesus is Magic."