The Inter defender clashed with Balotelli last season, but insists it was nothing personal.
"An error to sell Balotelli? At this point it can be an advantage for all," said Materazzi.
"If Mario has chosen this agent, then he wanted to leave Inter. And Inter, who has paid zero and sells for €35 million, makes a major profit.
"But I'm sure that Inter will give him up reluctantly because the club has always been his biggest fan and I'm pretty sure that Mario will cry, the day he says goodbye."