AFC defender Tim de Cler left the Amsterdam ArenA to join AZ Alkmaar on a three-year contract.
The 23-year-old left-back agreed to the move in a bid to play regular first-team football in the Eredivisie. A Dutch title winner with Ajax last term, he has not featured in Ronald Koeman's plans this season.
"Tim is known as a left-sided defender but he can play in more positions, we can use him on the whole left side," said Alkmaar technical director Martin van Geel.
"He is a guy with great potential who can grow here at AZ. He has had great training at Ajax and also has a terrific mentality." In all, De Cler made 75 appearances for Ajax following his debut in 1998.