The New York Racing Association has lost a major arbitration case brought by fired pari-mutuel clerks, dozens of whom walked off their jobs a year ago during the Preakness Stakes (gr. I) over a contract dispute.Details of the ruling in the binding arbitration case were not available Friday night, but both NYRA officials and representatives of the clerks confirmed the decision went against NYRA. "It was favorable to the clerks,'' said Sal Zammitto, chairman of the local Division of Pari-Mutuel Employees Union. He declined further comment until he discussed the ruling with his lawyer.The union leader said it was his understanding the arbitrator's ruling affected workers who were both fired and suspended by NYRA.William Nader, NYRA's senior vice president, also confirmed that the ruling went against the racing association, but said NYRA officials had not yet seen the arbitrator's decision.A racing industry source said the ruling could cost NYRA millions of dollars in back pay and could result in NYRA having to hire back the fired workers.A year ago, NYRA fired 59 clerks and suspended 30 others following a job action that happened May 21 at Belmont Park on the day of the running of the Preakness Stakes. At the time, the clerks were embroiled in a bitter contract dispute with NYRA.NYRA officials said 89 clerks called in sick that day, resulting in a shortage of workers to handle bets on live racing at NYRA and simulcast bets from Pimlico and elsewhere.Union officials at the time said they did not sanction the job action. NYRA officials said workers who returned to work by the start of the third race would not be fired, but suspended for five days without pay; 30 came into work by the third race. At the time, the pari-mutuel clerks had been without a contract for two years.