Zola was dismissed by the club after a dismal season which saw them narrowly escape relegation to the Championship.

But as the Italian attempted to steer the team out of danger at the foot of the Barclays Premier League table, his position was undermined by Sullivan, who took control of the club in January along with David Gold.

Sullivan apologised to supporters via the club's official website for a "shambolic" and "pathetic" performance against Wolves in March as Zola's position became increasingly isolated.

There were also suggestions that the Italian was unaware of moves to make the entire first-team squad, except for Scott Parker, available for transfer and that he was kept in the dark over a bid for West Brom midfielder Graham Dorrans.

Zola made a veiled reference to Sullivan's actions in a statement issued through the League Managers Association.

"I am extremely disappointed to be leaving West Ham United," said Zola.

"Over recent weeks, I have been the subject of various adverse comments, from within the club, which have been widely reported in the media.

"Despite what has been a very difficult period for me, I have thoroughly enjoyed my time at West Ham.

"I would like to sincerely thank the players and my staff for their continued support, hard work and commitment. I am extremely proud of their efforts, over a long and difficult season, in retaining West Ham's place in the Barclays Premier League.

"West Ham is a great club, with fantastic supporters and I wish the club every success in the future. The termination process of my contract is now in the hands of the LMA and I therefore will be making no further comment at this stage."

Zola, who was appointed as successor to Alan Curbishley in September 2008, only just managed to keep the club in the top flight.

The Hammers finished 17th to narrowly avoid relegation but his dismissal was a far cry from his first year in charge, when he guided the club to ninth place in the Premier League and was rewarded with a new four-year contract.

However, it was never an easy ride for the amiable Italian, who many critics claimed was too nice to cope with managing at the top level.

The success he enjoyed during that first season was always overshadowed by financial problems off the pitch under their former Icelandic owners.

The Italian clearly had the support of his squad but he had garnered little backing where it mattered and the end was not unexpected.

A statement from the club read: "West Ham United confirm that they have terminated the contract of Gianfranco Zola.

"The Board of Directors would like to thank him for his contribution and wish him well for the future. The Club will now be focusing its efforts on seeking a replacement.

"The Club will be making no further comment on this matter."

But LMA chief executive Richard Bevan insisted Zola would not have to wait for another crack at management and hinted that the Italian had been given little support by the club's board.

"Clear communication and a supportive framework at the top of a football club are essential for stability and delivering results," said Bevan.

"Gianfranco has had to manage his team through a period of significant uncertainty at the club and has shown dedication, resilience and commitment to his players, staff and the fans.

"Without a doubt Gianfranco is a talented young manager and I am sure that in the fullness of time he will be back working in the game."

Croatia boss Slaven Bilic, a former West Ham player, has emerged as one of the favourites to succeed Zola and former Hammers striker Tony Cottee would love to see him back at Upton Park.

"The fans want a manager who will bring success," said Cottee.

"The right man for me is Slaven Bilic, I think he is head and shoulders above the other candidates.

"I would love to see him return to West Ham.

"He has had a great experience with Croatia but they didn't qualify for the World Cup and if West Ham could give him an escape route I think he would take it. He has a lot of passion for the club and still has a place in London."

Former Manchester City boss Mark Hughes and current Portsmouth manager Avram Grant have also been linked with the post.

Hughes could be top choice for the co-owners although he has also been linked as a possible successor to Rafael Benitez at Liverpool should the Spaniard decide to quit Merseyside.