The prospects of altering the purse structure at Maryland thoroughbred tracks to provide more revenue for purses, breeders and track owners dimmed yesterday following a hearing before the House Ways and Means Committee of the Maryland legislature.

Del. Ben Cardin (D-Baltimore City), committee chairman, said afterward that he would await the fate of a similar bill in the Maryland Senate before calling for a vote by his committee. The bill is not expected to win Senate approval.

"There was genuine sentiment that there is a need to improve the purse structure," Cardin said. "There is a trend of tracks making less money and having everything cost more and more."

But the proposal to change the purse structure was not very popular with his committee, Cardin said, because it could cost the state almost $6 million annually in the income of almost $22 million it now gets from the tracks.

The Maryland racing industry, which has lobbied extensively for the bill, said purses would have to be raised from $50,000 to $70,000 a day if the state's major tracks are to remain competitive with those in New Jersey and Pennsylvania.

The bill submitted this year called for the state to surrender 2.34 percent (it presently gets 5.34 percent) of the takeout on pari-mutuel betting. One percent would go to increase purses, 34 of 1 percent would go to the breeders' fund and the other 1 percent would go to the tracks (Pimlico, Laurel, Bowie, and Timonium).

Reaction yesterday to bills extending the number of racing dates was "generally favorable," Cardin said.

The first would permit racing on Sunday, a proposal that could be controversial. The Maryland Racing Commission would be empowered to award the dates and probably would begin on an experimental basis, Cardin said.

Sunday harness racing has been a feature at Ocean Downs for a couple of years.

The second piece of legislation would give harness tracks 18 additional racing days each.

An observer of the two bills speculated that some tracks might not want to take on additional dates because of the extra costs they might involve.

"And, nobody in his right mind would open a track (on Sundays)in the fall when pro football is on," he said.