World champion Ronnie O'Sullivan is to "take some time off" from competitive snooker after refusing to sign the official players' contract.
The 36-year-old announced the news on his official website.
His statement read: "I have not signed the players' contract as I feel the contract is too onerous."
Barry Hearn confirmed the news on the World Snooker website, saying the body "simply can't make exceptions for one player's individual requirements".
He added: "Ronnie is at liberty to enter our events and play on the circuit at any time, once he agrees to abide by the rules of the players' contract."
Last month, O'Sullivan accused Hearn of "blackmailing" players and criticised the World Snooker chairman's controversial revamped 50-week, 27-event tour, which will take full effect next year.
By refusing to sign the players' contract, O'Sullivan has made himself ineligible to participate in any World Snooker-sanctioned event - including Premier League Snooker, a tournament he has won for the past two years.
O'Sullivan still intends to play snooker away from the official circuit, however.
"I still want to play snooker and visit those places around the world such as China where snooker is enthusiastically received and adored," he said in his statement.
"I hope to remain involved in the sport in some way in the future."
O'Sullivan clinched his fourth world championship with an in May, and afterwards spoke of his desire to take a six-month sabbatical from the sport.
He has recently spoken out over the changes Hearn has made to the sport's schedule, accusing the World Snooker boss of "blackmailing" players, and last month he told BBC Sport of his concerns.
In a statement issued on Thursday, WPBSA Chairman Jason Ferguson said he wanted to counter the "misconception that players are being 'forced' into playing certain events."
The statement went on to add that, "The contract is there to protect the players' income derived from the tour, and the sport as a whole. Once players have signed the contract they are free to choose which events they wish to play in.
"It is the WPBSA's duty to ensure that all of the players are treated equally and therefore it is our belief that all players should sign the same contract.
"We do not believe it would be in the interest of the membership as a whole if one player was allowed a different contract which could give that player additional appearance money. The World Snooker Tour is expanding rapidly and consistently on a global basis and it is set to grow further. We are looking for the support of the players as a whole in order to assist this growth.
"Ronnie O'Sullivan of course is free to sign the contract at any time during the season which would make him eligible to play in World Snooker events, but it is important to note that signing the players' contract does not in itself compel any player to enter any World Snooker tournaments."