Messi agreed on Tuesday to extend his contract with Barcelona by two years to 2018.
The Argentine forward began his career at Newell's Old Boys, where he played for five years until 2000, when he made the journey to Spain to join Barcelona's youth team, aged 13. He played for the first time in the senior squad at 16, in a friendly against Porto.
Teammates and World Cup winners Xavi Hernandez and Carles Puyol also agreed to new deals with the Catalan club.
"This news means that FC Barcelona has secured its ties with three of its most important players," the club said in a statement, adding the contracts would be signed "over the course of the next few weeks."
Club spokesman Toni Freixa said, "It was a very important matter for us all, but there was no problem when we came to negotiate and agree."
Messi is the heavy favourite to collect an unprecedented fourth successive world player of the year award. He has 90 goals in 2012, having surpassed Gerd Mueller's 40-year-old milestone of 85 in a calendar year, and there is still one game to go this month to improve on his astonishing tally.
His contract with Barcelona wasn't due to expire until June 30, 2016, but he's agreed to stretch his commitment to the club to June 30, 2018. Puyol and Xavi will extend theirs to June 2016.
Relying on Messi's uncanny ability to puncture defences, Barcelona remained in contention for three trophies; the Spanish league, Champions League and Copa del Rey.
On Sunday, his 22nd double of 2012, and sixth in six games, helped to beat Atletico Madrid 4-1, Barcelona's closest rival in the Spanish league.
Barcelona has attained a league record start of 15 victories in 16 rounds, and leads by nine points.
Puyol, the 34-year-old captain, had said he wanted to continue his professional career until he's 40, although he said he didn't want to "have to drag myself onto the field."
Although the defender joined Barcelona's youth team in 1995, he didn't debut with the first squad until October 1999, under coach Louis Van Gaal.
Central midfielder Xavi, 32, who has spent all of his professional career at Barcelona and is considered one of the game's most talented passers of the ball, first joined the youth club in July 1991 when he was 11.