Ferretti signed from Parma in 2005 and has always been in the background at City making just a handful of first team appearances. His contract was due to expire this summer.
Another City player looking to get away is Luigi Glombard. He's currently on loan at Oldham and has hinted he'd like to make it a permanent move.
"The game here is very different to France, it's a lot more physical," said 20-year-old Glombard. "I hope to do well for Oldham and this is a good opportunity for me."
Glombard scored for Oldham in last Monday's 1 - 1 draw against Bradford.