Brazil striker Neymar
Barcelona have agreed a deal to sign Brazil striker Neymar from Santos.
The 21-year-old will finalise a five-year-deal on Monday.
A Barcelona statement read: "FC Barcelona and Santos have agreed terms for Neymar. The 21-year old is one of the most promising footballers on the planet."
Neymar wrote on Instagram: "On Monday, I sign a contract with Barcelona. I want to thank the fans of Santos by these incredible nine years."
The statement in Portuguese added: "My feeling for the club and the fans will never change. Titles, goals, dribbling, celebrations and songs that fans created for me will be forever in my heart.
"It's a different moment for me. Sadness (farewell) and happiness (new challenge). May God bless me on my choices. I will always be in Santos!"
Neymar had been considering his future after Santos revealed they had accepted two offers for their star player, with Barcelona confirmed as one of the bidders and Real Madrid widely assumed to be the other.
His contract with Santos was due to expire at the end of next season.
Neymar will say goodbye to the Santos fans at Sunday's season-opening game against Flamengo before joining Barcelona after the Confederations Cup, which starts in Brazil on June 15 and finishes on June 30.
"I want to have the opportunity to once again take the field and hear the crowd scream my name," added Neymar.
The signing ends years of speculation about which team would be the first to persuade the player to make the move to Europe.
As well as Real Madrid, he has also been linked with Chelsea and Manchester United since making his debut for Santos in 2009.
Neymar led Santos to their greatest run since Pele stopped playing for the club in the 1970s, helping the team win the 2010 Brazilian Cup, the 2011 Copa Libertadores and three straight Sao Paulo State championships.
He is the club's leading scorer in the post-Pele era with 138 goals in 229 matches.
Neymar is also considered Brazil's key player for the 2014 World Cup.
In a statement, Santos said they had made every effort to keep hold of the player.
"Every effort was made to keep him in Brazil as long as possible, even offering to renew the current contract, which ends in July 2014," the statement said.
"At this time, however, it was not possible to compete with the terms offered from abroad, which affected the decision of the player to review his professional life.
"Due to the confidentiality agreement, and by mutual agreement, the terms of the transfer will not be disclosed by any of the parties."