World champion Ronnie O'Sullivan has abandoned plans to return to the snooker tour and will miss the rest of the season.

The 36-year-old has "personal issues which he needs to resolve", World Snooker chairman Barry Hearn announced today, and that means he will not return until next season at the earliest.

O'Sullivan announced after winning his fourth world title in May that he intended to take six months out from the sport, and although he returned to play in a low-profile Players Tour Championship event in September, he withdrew from last week's International Championship citing illness.

In a statement, World Snooker announced: "World Snooker has been informed that Ronnie O'Sullivan does not intend to compete on the World Snooker Tour for the remainder of the 2012/13 season."

Hearn said: "I have spoken to Ronnie and he has decided to withdraw from any events he has entered, and he will not be playing for the rest of this season. He has some personal issues which he needs to resolve and we wish him all the best for the future."

O'Sullivan has delivered frequent retirement warnings during his career, without carrying them out.

Before beating Ali Carter to land his latest world title, O'Sullivan said it could be time to bid farewell to the sport.

But after an impasse over signing a contract to play again this season, he agreed in August to continue, only to have second thoughts.

He said ahead of the International Championship, a new event in Chengdu paying similar prize-money to the UK Championship and reflecting the growth of snooker in the Far East, that it may have been a mistake to sign up.

Evidently O'Sullivan was not exaggerating, and for the time being at least the sport will have to cope without its biggest name, barely six months after losing another major star when seven-time world champion Stephen Hendry retired.

"It's not when I'm playing, it's when I go home, I'm a nightmare to be around" - Ronnie O'Sullivan

O'Sullivan made Hearn aware of his intention at the weekend, when he was asked to put it in writing.

Today saw O'Sullivan's letter arrive at World Snooker's offices, reiterating his plans to take an elongated sabbatical.

It is understood World Snooker officials do not expect O'Sullivan to go back on his decision, and that the Chigwell cueman expressed his regret at having to pull out of upcoming tournaments.

He had signed up for next month's UK Championship in York, a Players Tour Championship event in Gloucester, and January's Masters at Alexandra Palace, and was then expected to defend his world title at the end of the season.

In theory, O'Sullivan could be fined for pulling out of those tournaments.

World Snooker's affiliate body, the regulatory World Professional Billiards and Snooker Association, will determine whether such a punishment is appropriate.

O'Sullivan sought help from sports psychiatrist Dr Steve Peters to get his career back on track after losing interest in snooker, and it paid off when he triumphed in Sheffield this year.

"Deep down I'd love to play snooker, but I just got too involved, wrapped up in it," O'Sullivan said at the time.

"It's not when I'm playing, it's when I go home, I'm a nightmare to be around. I'm shut off from the world because I'm too wrapped up in trying to be perfect."

He also had issues with the organisation of the professional tour, and the growing demands on players during an increasingly busy season.

"There's certain pressures that I can't do with anymore," he said in May. "I asked for support from World Snooker and I never got it and I don't think I'll ever get it."