Katie Couric's Most Noteworthy Moments of 2011

Katie Couric & Brooks Perlin Split

Katie Couric and her boyfriend, entrepreneur Brooks Perlin, have called it quits after five years together, a rep for Couric confirms to PEOPLE.

The couple were “at different stages in their careers,” says a friend of Couric’s, who adds, “the split was inevitable.”

Couric, 54, and Perlin, 37, met at a 2006 fundraising event for cancer research. Couric’s husband, Jay Monahan, died of colon cancer in 1998, at age 42.