Singer Avril Lavigne has split with husband Deryck Whibley. The two were married in July 2006. (Dan Steinberg/Associated Press)

Avril Lavigne says she has split from husband Deryck Whibley after three years of marriage.

Lavigne, who grew up in Napanee, Ont., announced the separation in a blog posting on her MySpace page on Thursday after a published report in US Weekly broke the news.

"Deryck and I are separating and moving forward on a positive note," wrote Lavigne, 24. "Thank you to all my family, friends and fans for all your support."

Lavigne and Whibley, the frontman for Canadian pop-punk group Sum 41, began dating in 2004 before getting engaged during a trip to Venice, Italy, in 2005. They married on July 15, 2006, in Montecito, Calif., when Lavigne was 21 and Whibley was 25.

In her short blog entry, Lavigne wrote about the time they spent together.

"Deryck and I have been together for six-and-a-half years," she wrote. "We have been friends since I was 17, started dating when I was 19, and married when I was 21. I am grateful for our time together, and I am grateful and blessed for our remaining friendship.

"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."

Whibley's representatives did not immediately respond to a request for comment.