Barcelona have completed the signing of Valencia centre-back Jeremy Mathieu after meeting his €20m (£16m) release clause, the Catalan club have confirmed on its official website.

The Spanish giants were desperately looking for deffensive reinforcements after Carlos Puyol's retirement while new manager Luis Enrique wants Javier Mascherano back in midfield.

The Valencia defender had been earmarked as his top-priority since the beginning of the summer alongside Paris Saint Germain star Marquinhos.

And after weeks of tough negotiations the Catalans have agreed to meet his €20m release clause.

"FC Barcelona and València CF have reached agreement for the transfer of the French player, Jérémy Mathieu," Barcelona confirmed.

"Jérémy Mathieu will sign a contract with FC Barcelona for the next four seasons, plus an optional season more. The cost of the transfer is 20 million Euros and the buyout clause will be 50 million Euros."

Last week Mathieu publicly requested his club negotiate with Barcelona in order to let the Catalans to secure a cut-price deal.

"Valencia has an offer on the table from a very important club. I ask [Valencia] to understand the present situation and accept the offer. I have the opportunity to play at the biggest club in the world and it's the only one I want to play for at this moment, but I can't forget everything Valencia has given me and I want to leave in the best way possible," he said.

However, with Valencia demanding the release clause Barcelona have finally accepted to pay €20m even though he is 30 years old.

Mathieu becomes the fifth Barcelona addition this summer, following the arrivals of Luis Suarez, Marc-Andre Ter Stegen, Claudio Bravo and Ivan Rakitic.

Furthermore, they have also brought youngsters Rafinha and Gerard Deulofeu back to the Nou Camp after their respective loan spells at Celta Vigo and Everton.