Nicole Richie and her fiance, Adam "D.J. AM" Goldstein, have ended their relationship.

"They have decided to break off the engagement," Richie's rep told Us Weekly Wednesday. "The decision is mutual."

Richie, 24, and Goldstein, 32, had been dating sine 2003 and were planning a 2006 wedding.

The co-star of the E! Entertainment network's "The Simple Life" and the disco dj reportedly broke up a few days ago, a source told US Weekly.