MADRID -- Barcelona have signed promising Brazilian midfielder Arthur Melo from Gremio for 31 million euros (36.4 million US dollars) plus nine million in variables, the club confirmed Monday.

Arthur, who helped Brazilian club Gremio win the Copa Libertadores in 2017, has signed a six-year deal with Barcelona.

"Arthur stands out for his skill at protecting the ball and his eagerness to play directly up the field," Barcelona said in a statement.

The Spanish champions agreed on a deal for the 21-year-old playmaker in March and he will help fill the gap left by Andres Iniesta and Paulinho, who both departed this summer.

Barcelona initially planned to sign Arthur in January 2019 but with spaces to fill in midfield the deal was sped up.