Tabcorp will reduce its commission rate for select races in a Spring Racing Carnival bonus for NSW TAB punters.

 From as early as next month its 14.5 per cent deduction from win bets will shrink to 5.9 per cent for NSW TAB punters.

That's turning a $7 chance into a $7.70 dividend with the cut commission rate.

Tabcorp general manager of wagering marketing Ian Mackay said the reduced rate was a trial on the NSW TAB and he hoped it would soon be introduced in Victoria.

Punters will get eight to 10 minutes notice from Sky Racing, radio, on-course and online media outlets to cash in on the reduced rate.

UniTAB punters have received a similar incentive this year, but the commission reduction is not notified until after the race.

The reduced take on the win bet is a key weapon in Tabcorp's fight with corporate bookmakers.

"Tabcorp is committed to providing our TAB customers with a compelling wagering offer," Mackay said.