Brandon Routh in a scene from Superman Returns

Superman star and former model Brandon Routh, 25, is engaged to his girlfriend of three years, actress Courtney Ford.

Breaking the news to People, Routh's rep, Kacey Spies, said, "They are very happy,"

Rumors that Routh may soon get hitched surfaced after he was spotted buying a dazzling diamond engagement ring, having spent an hour choosing it at an elite jewelry store in Beverly Hills, California. He finally settled on a band set with diamonds, which cost him 42,000 dollars.

The couple have been dating steadily since 2004.

Speaking with PEOPLE in June, Routh had termed Ford, 28, his personal kryptonite.

"She brings me to my knees," he said.