DENVER (Reuters) - A former U.S. Marine who prosecutors say raped a 22-year-old woman inside a concourse at Denver International Airport in 2011 was convicted of sexual assault on Monday, prosecutors said.

A Denver District Court jury found Noel Alexander Bertrand, guilty of sexual assault with force for attacking the woman in the early morning hours of April 12, 2011, Denver District Attorney's spokeswoman Lynn Kimbrough said in a statement.

The victim testified during the three-day trial that the pair met at an airport bar, and Bertrand became violent after she rejected his sexual advances, slamming her head on the floor and raping her inside the airport's "A" concourse.

Two Frontier Airlines mechanics testified that they witnessed the attack and intervened, detaining Bertrand until Denver police responded and arrested him.

Bertrand took the stand in his own defense, testifying to the jury of 6 men and 6 women that the pair engaged in consensual, rough sex.

According to a 2009 article in Leatherneck Magazine, a publication for U.S. Marines, Bertrand served as an embassy guard in Ireland, Venezuela and Qatar before leaving the corps.

Bertrand potentially faces life in prison when he is sentenced on November 30. (Reporting by Keith Coffman; editing by Dan Whitcomb and Todd Eastham)