England goalkeeper Tom Heaton has committed his future to Burnley by signing a new contract until June 2018.
Wolfsburg have moved to sway Newcastle away from a move for Bas Dost by claiming the striker would command a fee around the £29million mark.
The Colombia international, 26, moved to San Siro on a season-long loan last summer and his performances for the Rossoneri - who finished third in Serie A - have earned him a three-year contract in northern Italy.
A statement published on acmilan.com read: "AC Milan wishes to communicate they have made the signing of Cristian Zapata from Villarreal permanent.
"The defender's contract will run to June 30, 2016."
Zapata, who previously spent five years in Italy with Udinese, has made 28 appearances in all competitions for Milan.