The former Roma star will stay with AC Milan on loan until the end of the season with a view to a permanent deal.
A statement from AC Milan read: “AC Milan announces the signing of Inter Milan player Amantino Mancini on loan until the end of the season with an option to acquire the player’s sporting rights once the loan deal ends.”
Mancini has failed to become a hit at Inter since joining the club from Roma in the summer of 2008.