The twenty seven year old, on the first day of pre-season training, has made the move for an undisclosed fee.
He played only four games in three and a half years since joining from Charleroi for £1.5m during Kevin Keegan's reign.
Now he has returned to Belgium to end his City career that saw him switch from a midfielder to a target man.
He went for a brief loan spell to Coventry last term, and was never close to nailing down a first-team slot with City.
He made just one appearance in the Premiership during the season just ended.