Nicolas Anelka has said on Twitter that he has terminated his contract with West Brom with "immediate effect".
He said: "Following discussions between the club and myself, certain conditions have been set which I can't accept.
"In order to preserve my integrity, I've terminated my contract with West Brom with immediate effect."
Anelka, whose 12-month contract runs out at the end of the season, would only be eligible to play in Albion's final five Premier League games.
He was given the punishment by the Football Association's independent regulatory commission for making the gesture, which has anti-Semitic links.
The striker denied his use of the sign, described as an "inverted Nazi salute", was anti-Semitic and the commission accepted there was no intent by Anelka to be anti-Semitic.
The FA had initially wanted a tougher punishment for the player but opted not to appeal against the decision.
Anelka, who also did not appeal against the ruling, is due to begin his five-game suspension in Saturday's Premier League game at Swansea.
He claims he made the gesture in support of his friend Dieudonne M'bala M'bala, a French comedian who has been convicted seven times of anti-Semitic crimes.
West Brom were not available for comment on Friday evening.