AS.com

Lionel Messi has signed a new contract with Barcelona that will keep him at the club until 2018, when he is 31 years old.

The Argentine put pen to paper on Thursday evening at the Barcelona offices, alongside club president Sandro Rosell.

The Argentine has renewed his contract with the Catalan club six times in the last eight years, and his latest deal will earn him 11 million euros per year after tax.

Messi has a peculiar contract, which explains why it has had to be modified so often. The bonuses which 'La Pulga' earns are included in his salary. For example, when he wins a trophy with Barcelona, the amount he would receive for the bonus goes towards his annual salary for the following year.

Messi has accepted the club's offer to renew his contract until 2018, but has not allowed the club to touch his buy-out clause, which will remain at 250 million euros, an amount which, in theory, is high enough to dissuade even the richest clubs in the world from making a swoop for him.

The forward signed his first contract renewal in 2005 after winning the under-20 World Cup with Argentina. Three months later, after wowing the Camp Nou in the Gamper trophy against Juventus, he increased his wages.

In January 2007 he signed a contract until 2014 with a buy-out clause of 150 million euros, and then in June the following year, after Ronaldinho had left, Barça offered him an increased wage. The last time he came into the Barça offices to sign a contract was in September 2009, when he renewed until 2016, raising his buy-out clause to 250 million euros.

Although this will be Messi's sixth renewal, there could yet be more new deals to come, due to the fact that his contract may have to be adapted to include his bonuses.

What is unclear is whether he will stay at the club beyond 2018. Although he has often said he would like to hang up his boots with Barcelona, he has also let it be known that he would like to see out his playing days in his native Argentina, with boyhood club Newell's Old Boys.

But in any case, Messi's recent declarations indicate he will not be leaving Catalonia any time soon.

"I will stay at Barcelona as long as the fans and the club want me here," he said.