World champion Ronnie O'Sullivan has quit the sport's main tour, having refused to agree to a stringent player contract imposed by Barry Hearn's World Snooker organisation.
O'Sullivan, who won his fourth world title last month, had threatened to take time out of the game, complaining about the impossibility of balancing family life with the need to travel extensively under Hearn's new regulations.
And the 36-year-old has now refused to sign the contract, thus ruling him out of all World Snooker competitions.
"I have decided not to enter any tournaments for the time being, including this year's Premier League and forthcoming WPBSA ranking events," O'Sullivan said in a statement.
"I have not signed the player's contract as I feel the contract is too onerous and I am in a stage of my career where I don't wish to make this commitment."