Avril Lavigne and Deryck Whibley
09/17/2009 AT 07:35 PM EDT
Life's going to be a little less complicated for Avril Lavigne
After months of facing rumors about trouble in their marriage
, the pop star and husband Deryck Whibley announced Thursday that they are separating on good terms.
"Deryck and I have been together for 6-an-a-half years. We have been friends since I was 17, started dating when I was 19, and married when I was 21," Lavigne, 24, writes on her Web site
. "I am grateful for our time together, and I am grateful and blessed for our remaining friendship."
She adds: "I admire Deryck and have a great amount of respect for him. He is the most amazing person I know and I love him with all my heart. Deryck and I are separating and moving forward on a positive note."
In a message on the MySpace page for his band Sum 41, Whibley also posted a message about the split. "The past 6 and a half years have been the most amazing years of my life. It's sad it has come to an end but Avril and I are still family and moving forward in the most positive way possible," reads the note. "Our decision to part ways is amicable and she holds a special place in my heart and forever will be a great and amazing friend. Thanks to all our family, friends and fans for all the support."
Whibley, 29, and Lavigne, who are both from Canada, tied the knot
in July 2006 at a private estate in Montecito, Calif. But save for one appearance together last month, the pair had been living apart for some time.
"They really want the best for each other," a source tells PEOPLE. "They're handling everything as amicably as possible." In fact, says the source, Whibley produced much of Avril's upcoming album.