Inter Milan signed Italian national team striker Antonio Cassano from AC Milan, the two clubs said on their websites.
Striker Giampaolo Pazzini moved from Inter to AC Milan as part of the deal. Pazzini, 28, scored 19 goals after joining Inter in January 2011.
Cassano, 30, missed a most of last season following heart surgery in November, finishing with three goals in 16 games. He also had one goal as Italy reached the final of the 2012 European Championship, where it lost to Spain.