(CNN) -- French soccer star Nicolas Anelka has decided to quit English Premier League club West Bromwich Albion following his punishment for making a controversial "quenelle" gesture.
Anelka was last month banned for five matches and fined £80,000 ($130,000) by the English Football Association following an incident during a match in December.
Anelka was widely criticized by performing the "quenelle" -- which involves pointing a straightened arm downwards while touching the shoulder of that arm with the other hand -- after scoring against West Ham.
The gesture, which he said was dedicated to his comedian friend Dieudonne M'Bala M'Bala -- who uses it as part of his act -- is believed by some to be a Nazi salute in reverse and has been linked with anti-Semitism in Anelka's homeland.
An Independent Regulatory Commission was asked to consider if the gesture was "abusive and/or indecent and/or insulting and/or improper," and "included a reference to ethnic origin and/or race and/or religion or belief."
Both charges were proved, said the commission, but it added it did not believe Anelka to be a racist.
West Brom, which is battling to avoid relegation from the top flight, decided not to appeal against the judgment.
"I have taken the decision to free myself and put an end to the contract linking me with West Bromwich Albion," Anelka wrote in French on his Twitter page on Friday -- his 35th birthday.
"Following talks between the club and me, propositions were made to me in order to reintegrate me into the squad under certain conditions that I cannot accept.
"Wishing to retain my integrity, I have therefore taken the decision to free myself and put an end to the contract linking me with West Bromwich Albion to 2014, with immediate effect."
West Brom, however, said Friday it had yet to hear officially from Anelka -- whose ban was due to start this weekend, with the club outside the Premier League's bottom three on goal difference, having 10 matches to play.
It said his Twitter statement was "highly unprofessional" and constituted "gross misconduct" -- and said it had given the striker 14 days' notice of termination as required by his contract.
"The club notes Nicolas Anelka is unwilling to agree to the conditions set by it which may have enabled his suspension to be lifted and for him to resume training," it said in a second statement.
"These conditions were, firstly, that the club required Nicolas Anelka to apologize to it, its supporters, sponsors and the wider community for the impact and consequences of his gesture made on December 28 and secondly, that he accept a substantial fine."
The FA had considered appealing against Anelka's punishment, having been criticized by anti-racism groups over its alleged leniency.
"We do not consider there is a real prospect of successfully appealing to extend the sanction imposed," the FA's director of governance Darren Bailey said Thursday.
"The grounds of appeal available to us are limited to legal challenges or to circumstances in which the sanction imposed is 'so unduly lenient as to be unreasonable'. That is a high test."
Anelka joined West Brom on a one-year deal in August, and his two goals against West Ham on December 28 were his first for the club.
He continued to play while the matter was being investigated, but was sidelined in February due to a knee injury.
Anelka has played for many of Europe's biggest clubs, including Real Madrid, Juventus, Chelsea, Arsenal, Liverpool, Manchester City, Paris Saint-Germain and Fenerbahce, as well as a short but highly-paid stint with Chinese team Shanghai Shenhua.
He played for France on 69 occasions, winning the 2000 European Championship, but his only World Cup appearance in 2010 ended in disgrace as he was expelled from the squad following an argument with coach Raymond Domenech.
Anelka was subsequently banned for 18 matches by the French federation, but decided to end his international career rather than serve it.