Barcelona's Joan Laporta believes Lionel Messi will spend his entire career with the Catalan giants after signing a new deal.

The Argentina forward has committed his future to the club until 2016, when he will turn 29.

And despite there being a 250million euros (£225million) release clause in his contract, Laporta expects Messi to retire as a Barcelona player.

"This is the best news Barca can receive today," Laporta said of the deal that makes Messi the club's highest-paid player.

"It is important to have a player with his human qualities and his football ability. This deal recognises all that he gives to Barcelona.

"It is impossible to imagine the team without a player like Messi. We expect Leo to retire here with Barca."

Messi, who was previously signed to Barcelona until 2014, has had his release clause increased from 150million euros in a move to end any further speculation about his future.

The 22-year-old joined Barca as a youth-team player in 2001 and has won a host of trophies with the Catalan giants, including last season's unprecedented treble.

Messi signed his contract this afternoon at the Nou Camp in the presence of Laporta, his brother Rodrigo, club vice-presidents Rafael Yuste and Joan Boix, technical secretary Txiki Begiristain, and football director Raul Sanllehi.

"With this new contract, Leo Messi ensures he will be azulgrana for 15 years, having started his career at Barca in 2001, in the youth sectors of the club," a statement from Barcelona said.

The announcement had been expected and earlier coach Pep Guardiola expressed his delight at the news.

"It's an immense piece of news for the club and for the player that Messi is renewing his contract," said Guardiola, "as it also was when Victor Valdes and Xavi did so.

"People go to football to see the best and that's what they are.

"It's a privilege for Barca to have some of the best footballers like Messi."