Barcelona have signed Turkey captain Arda Turan from Atletico Madrid for an initial fee of £24m.
The UEFA Champions League and La Liga winners said the four-year deal for the 28-year-old could reach £29m with potential add-ons.
The former Galatasaray player will not be able to play an official game for Barcelona until January 2016 due to a transfer ban imposed by FIFA for breaching rules over the signings of underage players.
Turan joined Atletico from Gala in 2011 and went on to play 127 games for the Rojiblancos, winning the Europa League in his first season before clinching the Copa del Rey in 2012-13.
He scored three goals and set up four more in 30 league appearances the following season as Atletico won their first Spanish league title in 18 years.
He started 28 league games as Atletico finished third in 2014-15 to qualify for next season’s Champions League.