Atlantic City's first gambling casino won a daily average of $438,504 in its first six days of operation, the casino announced yesterday.

Resorts International Hotel Casino said the crowds that jammed the gambling hall from its opening minute May 26 lost an average of $242,536 daily to the 893 slot machines and $195,968 each day on the gambling tables - dice, roulette, black-jack, baccarat and "big six wheel."

Resorts International, which gambled on Atlantic City by investing proved the state-wide referendum legalizing gambling in the coast resort, said that the total customer losses represent its gross revenues before any expenses or taxes.

Resorts officials said the casino's expenses for the six days will be made public on June 30. New Jersey receives an 8 percent tax on the casino's winnings.

Resorts said that its casino had a total win of $2,631,024 for its first six days despite mechanical problems which kept about 19 percent of its slot machines out of operation at all times.

The casino also said that between 11 and 21 percent of the 86 gambling tables were closed at any one time because the casino did not have enough licensed dealers to keep all of its tables open.

On June 2, the New Jersey Casino Control Commission licensed additional dealers which, Resorts said, "should permit full utilization of all table games."

About June 16, Resorts plans to open an extension to its casino which will increase the gambling space by 60 percent - providing room for 410 more slot machines and 62 additional gambling tables.