Ricardo Vaz Te has had his contract with West Ham terminated by mutual consent.
The 28-year-old forward has been linked with a move to Turkey and can now pursue any new deal as a free agent.
The Portuguese, who began his senior career under Sam Allardyce at Bolton and later had spells with Hull, Hibernian and Barnsley, joined West Ham in January 2012 and scored the winner in the Championship playoff final win over Blackpool that May.
However, he has fallen down the pecking order since the club's subsequent return to the Premier League, and has made only five first-team appearances this season.
"It has been a pleasure to be at a club like West Ham,'' Vaz Te said West Ham's official website. "It was a fantastic opportunity and I am so grateful for having played here. Everything I achieved here and all my game time and my life off the pitch has been amazing.
"I will never forget that day at Wembley -- it was so special for me and for all of the fans involved. That is the kind of moment you don't intend to forget. I'm very fortunate to have had that moment and I'm pleased I could do that for the fans, for the club and for my team-mates.
"I would like to thank the West Ham fans and to tell them to keep supporting the club through what is going to be an exciting time over the next few years.''
Meanwhile, West Ham are in talks with potential new sponsors after current backer Alpari UK went bust.
The foreign exchange broker's clients recorded huge losses in the wake of Switzerland's shock move to abandon the country's peg to the euro.
The company said the decision to remove the currency floor resulted in the majority of clients sustaining losses which exceeded their account equity.
Alpari said on Friday: ''Where a client cannot cover this loss, it is passed on to us. This has forced Alpari (UK) Limited to confirm today that it has entered into insolvency.''
But in a statement of their own, West Ham said they would not be affected by the company's collapse.
"West Ham United has enjoyed a good working relationship with Alpari (UK) Limited since 2011 and is therefore saddened by today's news that it has entered into insolvency. The club would like to offer its sympathies to any Alpari staff affected by the announcement, particularly those that have worked closely with us over the past few years,'' the club said.
"The board would like to reassure supporters that Alpari (UK) Limited's situation will have no impact on West Ham United. The club remains in a strong financial position and just last month published accounts showing record revenues and a group profit of 10.3 million pounds before tax.
"The club has received huge interest and is already in advanced discussions with potential new shirt sponsors for next year.''