Barcelona president Josep Maria Bartomeu has insisted that he "was always convinced" superstar forward Lionel Messi would sign a new long-term deal.

The five-time Ballon d'Or winner put pen to paper on a four-year contract at Camp Nou on Wednesday to end any niggling suspicions that he could depart as a free agent next summer.

Messi had been in talks with the Catalan giants since the turn of the year, with the delay in agreeing fresh terms reportedly alerting his former manager Pep Guardiola at Manchester City.

Bartomeu never truly feared losing the Argentina international, but admits to being delighted to see him go the same way as teammates Luis Suarez and Neymar in officially committing.

"Personally, I was always convinced that he'd renew his contract for the next four years," he told reporters. "This is great news not just for Barca fans, but for the football world in general. Leo Messi's story is one of loyalty and commitment.

"He's the greatest player in football history and has been at Barca since he was just 13. And the story continues. The fact he's staying for another four years means that things are going well, and will go well, and we are very happy for him and the Barca family.

"We also renewed Neymar and Suarez's contracts and it's not easy to convince such quality players to stay in such a competitive world as that of modern football. A lot of clubs are after our stars, but they want to stay here and keep enjoying this successful era.

"Leo Messi has always said that he'd like to see out his professional career here at Barca and this contract says it all. It sends out a message of unity between Messi and Barca."

Messi has scored 507 goals in 583 outings for Barca in all competitions, helping the club to eight La Liga titles and four Champions League crowns.