The 'Smile' singer, Lily Allen, teamed up with producer Ronson for her hit debut album 'Alright, Still', but has ignored his offer of help for her next LP.
Ronson said: "Lily has been working on her new album but I'm probably not going to be on it as she hasn't been returning any of my calls.
"Most of the people I work with, I'm lucky enough to be friends with too. But then you never really know what's going to happen."
Lily - who released 'Alright, Still' 18 months ago - also sang on Ronson's cover of the Kaiser Chiefs' hit 'Oh My God' but failed to join him on stage to perform it at his Electric Proms concert in October.
He is quoted by Britain's The Sun newspaper: "She didn't come but she had another commitment and she explained why and it's fine. I'm not going to lie and say I wasn't disappointed - but it's not like she just didn't show."
Lily, 22, recently denied rumours she was going to retire from the music business at 25.
She said: "Of course I'm not going to retire. This was the biggest joke in my life and I just cannot believe people would actually believe this junk.
"I talk c**p all the time and they all know it, so how come this time they didn't get it. Silly people. I am having the best time of my life."
TAGS: Entertainment Lily Allen