Muntari originally joined in January until the end of the season yet the Ghanaian has impressed, making the most of the Rossoneri's injury problems, enjoying 13 Serie A appearances for the club, scoring three goals in the process.
The former Udinese man is out of contract at Inter this summer and his representative, Federico Pastorello, has confirmed his client will continue to play under Massimiliano Allegri's tutelage.
“Muntari will continue together with Milan for the next two years,” the agent told MilanNews.
“The renewal is a pure formality and there will be no problems. Milan will make the announcement soon. The lad was able to talk to vice-president Adriano Galliani before the end of the season, so he was reassured.
“When I was given the mandate to sell the player, I spoke to the lad and realised he wanted to gain experience and have satisfying moments after the problems he had with Inter.
“In that sense [Milan vice president Adriano] Galliani realised the good opportunity that was falling into his lap. He thought that Sulley had quality, but also great motivation, and that made the difference.”
Despite his impressive form for Milan, Muntari could only help the Italian giants to a second-placed finish in Serie A behind Juventus.