Benfica says it has sold midfielder Nemanja Matic back to Chelsea at a healthy profit.

The Portuguese club said in a statement to the Lisbon stock exchange Wednesday it sold the Serbian international for 25 million euros ($34 million). Chelsea confirmed the 25-year-old had signed a five-and-a-half-year contract.

The 25-year-old left Stamford Bridge in 2011 as a makeweight in an agreement that took Brazilian defender David Luiz from the Stadium of Light to London.

Matic grew into a key player at Benfica, helping the club reach last season's Europa League final where it lost against Chelsea.

Chelsea coach Jose Mourinho said Matic "has grown as a player in Portugal and has become a fantastic all-round midfielder."