Galliani said that Balotelli, who joined from Manchester City in January, is the future of the Rossoneri.
"Balotelli will not be sold; he's absolutely not on the market," Sky Sports News quotes Galliani as saying.
"We count on him. He's a world star and we will build our future around him."
Balotelli has scored 12 goals in 13 games since signing for Milan.