BARCELONA -- Lionel Messi has not yet signed his new four-year contract with Barcelona but the club say they are already preparing to offer him a lifetime deal, similar to the one signed by Andres Iniesta earlier this month.

Messi, 30, agreed a new contract with Barca in July, but he has not yet sat down to sign the terms with president Josep Maria Bartomeu.

However, Bartomeu has assured fans that everything is in order, with Messi's father and representative having already signed the contract, and that it is just a matter of finding the right time to fulfil the protocol.

In the meantime, Barca CEO Oscar Grau says a contract for life is already in the pipeline for the Argentina captain.

"Messi signed a four-year deal in June, but the club will offer him a lifetime contract," Grau said at Barca's annual general meeting on Saturday. "The idea is for Leo, who has been here since he was little, to stay here for life because he is an icon. After his playing days we want him to continue to be linked to the club."

Lionel Messi agreed a new contract with Barcelona in July but has yet to sign it. Alex Caparros/Getty Images

There has been concern throughout the last year as Barca have allowed Messi's deal to run dangerously close to its 2018 expiry.

Premier League side Manchester City, managed by former Barca boss Pep Guardiola, have been most prominently linked with Messi.

But Barca have always maintained that Messi would sign a new deal, telling ESPN FC last November that they had no doubts about the forward extending his stay at the Camp Nou.

Messi joined Barca as a 13-year-old and made his first-team debut as a 17-year-old.

He has since gone on to become Barca's record goal scorer with 522 goals, has won 30 trophies and is third in the club's all-time appearance rankings with 596, behind only Xavi Hernandez (767) and Andres Iniesta (641).