Bookmakers have reached agreement with the horse racing industry to put up to £72.4m into the sport next year.
But the chairman of the British Horseracing Authority Paul Roy says the levy is too low and "unreflective of the modern betting environment."
The deal means the Government will not be called in to decide what bookies pay to the sport as they did last year.
Roy believes the levy system, providing 50% of prize-money, is out of date and is "costing racing vital revenues".
Culture Secretary Jeremy Hunt had to set the figure last year because agreement could not be reached.
For the 51st Levy, payable from April, William Hill, Ladbrokes and Coral have committed to a base figure of £45m and, in addition, Betfair has undertaken to provide £6.5m. A total of £72.4m is estimated.
Racing fixtures in the UK in 2012 will be down by 30 to 1,450
Roy issued a statement on behalf of the BHA in which he said: "The sport does have a degree of certainty moving forward, and can immediately finalise the 2012 fixture list, but our return from the betting industry remains far lower than our commercial value, and the levy remains unreflective of the modern betting environment.
"Offshore operators and the failure to address betting exchanges' different business model are still costing racing vital revenues.
"This year's last-minute discussions have again laid bare the imperfect and out-dated processes within the levy mechanism."
The Levy Board and the bookmakers were satisfied with the agreement.
Levy Board chairman Paul Lee said: "I believe the offer that has been accepted should deliver to the sport significant benefits.
"The offer of guaranteed contributions by the major operators provides more certainty for all parties and valuable assistance for the Levy Board's financial planning."
Will Roseff, chairman of the bookmakers committee, the betting industry's negotiating body for the levy, added: "We hope that this year's settlement on the 51st Levy offers a springboard for discussions on its long term future, removing government from the process entirely."