FC Barcelona confirmed on Wednesday the signing of French central defender Jeremy Mathieu after paying the 30-year-old's 20 million euro (27 million US dollar) buyout clause.

Mathieu has agreed a four-year contract with the option of a fifth campaign with Barcelona who have imposed a 50 million clause on the defender.

He had been due to fly to Peru with Valencia was in Madrid when the arduous negotiation between Valencia and Barca were finally concluded to make him Barca's fifth signing of the summer behind goalkeepers Claudio Bravo and Ter Stegen, midfielder Ivan Rakitic and striker Luis Suarez.

The Frenchman is a much needed addition for Barca's central defense, which has looked to be one of the club's weaknesses in recent season and which looks short of members after the retirement of Carles Puyol and the likely decision of new coach, Luis Enrique to return Javier Mascherano to his preferred central midfield role.

That would have left just Marc Bartra and Gerard Pique as specialist central defenders and as such the club could still look to sign another defender before the end of the summer.

Mathieu arrived at Valencia as a midfield player, but was pushed back to play at left back before spending last season in the heart of the defense, where his height, pace and the fact he is naturally left footed are important assets.

He will officially be presented to the fans and the press on Thursday.