Katharine McPhee, the American Idol finalist, Star of Smash and upcoming CBS drama Scorpion, and popular for her hit single terrified; has officially split from her husband, Nick Cokas.

McPhee's representative confirms exclusively to PEOPLE, "After six years of marriage, and having been separated for the past year, Katharine McPhee has filed for a dissolution of marriage from Nick Cokas. The two have an amicable relationship and will remain friends. They ask that people respect their privacy during this time."

Late last year, the couple were rumored to be having irreconcilable differences and that Mcphee is already said to be falling out of love with Cokas. Also, McPhee was photographed kissing her Smash director Michael Morris, who is wed to actress Mary McCormack.

According to people, Morris and McCormack have since reportedly reconciled, and this past spring, McPhee and Cokas were apparently working on their marriage, and were seen walking their dogs together and smiling.

A source close to McPhee says no outside parties ultimately played a role in the split. "It was just time," the source tells PEOPLE. "They'd grown apart and weren't right for each other anymore."