Three casinos in the US state of Pennsylvania have been hit with fines in excess of $350,000 - the most ever levied in a single meeting of the state's Gaming Control Board - for instances of under-age gaming and violations involving slot machines or software.

Pennsylvanian law stipulates that it is illegal for persons under 21 years of age to wager, play or attempt to play slot machines or table games or to remain in an area where they are operated. All three casinos had previously been fined for similar under-age gaming offences.

Pennsylvania’s Gaming Control Board fined Mount Airy, the operator of Mount Airy Casino Resort, $160,000 following incidents in which seven under-age individuals  - six of which were aged either 16 or 17 - gained access to the gaming floor in February this year.

The board fined Holdings Acquisition, the operator of the Rivers Casinos, $150,000 for 11 instances of permitting under-age gaming and five incidents in which slot machines that had not been subjected to proper testing and certification were put into operation.

Mountainview Thoroughbred Racing Association, meanwhile, received a $40,000 fine for allowing a 20-year-old to play both slots and tables at its Hollywood Casino at Penn National Racecourse in November last year.

"While we certainly have a responsibility to work with casinos and maximise the revenue and jobs that benefit Pennsylvanians, our most important responsibility is to protect the public by ensuring that casinos are adhering to the law and regulations," said the board’s chairman, Greg Fajt.

"In these instances, it was imperative that the board act in a manner that clearly tells those companies that have been given the privilege of holding a Pennsylvania gaming licence that violations are both unacceptable and have consequences."

The authorities also fined slot manufacturer WMS Gaming $5,000 for shipping slot machine software to Presque Isle Downs and Casinos that had yet to be tested or approved by the state’s gaming laboratory.

This software, however, was identified as unapproved before being offered for public play.