The 20-year-old, who is the younger brother of Thiago Alcantara, has put pen-to-paper on a deal until 2016.
The Blaugrana have confirmed that his minimum fee release clause has been increased to €30m (£25.5m).
The attacking midfielder, who has represented both Spain U19 and Brazil U20, is expected to join Celta Vigo on a season-long loan within the next few weeks.
Read the original article on Football Espana - The ultimate website for English-speaking fans of Spanish football
- Sports & Recreation
- Thiago Alcantara