Mary-Kate Olsen and Boyfriend Call It Quits

By Liz McNeil and Serena Kappes

09/07/2004 at 07:35 PM EDT

New college student Mary-Kate Olsen, 18, and boyfriend David Katzenberg, 21, have broken up, a source tells PEOPLE.

Olsen and Katzenberg, who began dating late last year, ended their relationship a week ago in Los Angeles before both flew east to attend college – she at New York University, he at Boston University. "It was a mutual parting of the ways and amicable," says the source. "Being at different schools played a part. It's reasonable for her to start school fresh." (Olsen's rep declined to comment on the relationship.)

Olsen and Katzenberg, the son of DreamWorks cofounder Jeffrey Katzenberg, were first spotted kissing last December and were soon seen out and about in Los Angeles, attending Lakers games and going to clubs together. Katzenberg remained by Olsen's side during her recent battles with an eating disorder (she spent six weeks in a health facility this summer).

Rumors that Mary-Kate, who begins her first day of classes at NYU on Wednesday, is already back on the dating scene aren't true, says the source: "There is no dating going on at all. She is simply meeting new people and making new friends."

Mary-Kate is keeping busy in her new hometown. Along with starting classes, she and twin sister Ashley may attend the U.S. Open finals and will make the scene during New York's Fashion Week, which starts Wednesday.