NEW YORK: Avril Lavigne has dismissed rumours her upcoming album has been hindered by her fractured working relationship with ex-husband Deryck Whibley, insisting they are still the best of friends.

Lavigne filed for divorce last year (09) after three years of marriage, citing "irreconcilable differences".

Her fourth studio album, Pink Crust, is being produced by Sum 41 rocker Whibley, but the disc was pushed back from its original November (09) release date and is reportedly now only likely to be ready in the summer (10).

But the Complicated hitmaker has brushed off rumours the project's delay is the result of tension between her and her ex in the studio - because the former lovers have a great working relationship.

She tells Ryan Seacrest's KIIS FM radio show, "We still work together all the time. He's one of my best friends...

"We've been friends for a really long time, and we always will be. We're family and we have a connection. (We) work really well together."