In a major loss to Sydney racing, Con Kafataris, arguably the nation's biggest bookmaker, says he will suspend his operations at the end of the autumn carnival.

Kafataris said his on-course business has become "totally unsustainable" due to draconian State Government restrictions imposed on bookmakers.

"My NSW on-course license is loss-making and I have no viable future unless the Government and racing bodies remove restrictions to allow NSW bookmakers to be on a level playing field with corporate bookmakers and the TAB," Kafataris said last night.

"It's a sad day for me personally because I have been a NSW bookie for 34 years. I still enjoy a day at the races but I can't see the point of continuing when there is no future in it."

Kafataris held more than $120 million in bets on-course at Sydney racetracks during 2008-09 but said his volume of trade had dropped alarmingly this season.

"If I was to continue to field on-course until the end of the season I would probably hold around $70 million," he added.

Kafataris said once the Sydney autumn carnival ends in April, he would concentrate betting activities on his thriving corporate bookmaking firm, Centrebet, which will have turnover of more than $1.2 billion this financial year.

The fearless bookie is prepared to take on all the big punters and if he does vacate his stand on Sydney racetracks, it will leave a void impossible to fill in the bookmaking ranks.

Kafataris said outdated regulations are stopping NSW bookies offering a competitive range of products under flexible operating conditions.

He maintains bookies should be able to take phone and internet bets on any day, including when we are not at the racecourse.

"This will keep bookies in business and grow racing industry revenues," Kafataris said.

"[But] we have our hands tied and my best on-course betting customers have basically been 'wooed off the track' and in most cases out of NSW."

NSW Racing Minister Kevin Greene countered that the State Government has made substantial changes to improve the competitiveness of the local bookmaking industry.

The Minister said his government had given bookies "access to phone and internet betting, sports betting as well as not allowing local TABs to have fixed odds betting up to the jump like they do in Victoria."

"The NSW Government has also given NSW bookies a $5 million injection because we dropped the 1 per cent turnover tax previously imposed.

"Other jurisdictions still charge turnover tax on bookmakers," Minister Greene said.

"My responsibility as Minister is to the whole industry, including the 50,000 people who have jobs in racing, not just millionaire bookies who have done very well from racing in NSW."

Kafataris then returned serve by declaring NSW bookmakers have "always paid the racing industry and we want to continue to contribute".

"Looking at NSW horseracing as an example - I pay $1.50 for every $100 wagered with me at the track," he said.