(ANSA) - Rome, August 13 - Fiat has failed in a bid to overturn an order to hire 145 members of left-wing trade union FIOM at its Pomigliano d'Arco plant near Naples, the union said on Monday. FIOM chief Maurizio Landini said the Rome appeals court had ruled the carmaker's petition against a June ruling by a lower court as inadmissible. Fiat, Italy's biggest private-sector employer, did not rehire any FIOM members when it set up a newco to run the factory in 2010 after the union rejected a revolutionary deal on flexible working practices there. A Rome court in June ruled this was unfair discrimination, ordered Fiat to take on the FIOM members and awarded 19 of them 3,000 euros in damages. FIOM and Fiat clashed furiously over the factory-specific Pomigliano deal, which was negotiated outside Italy's traditional national contract bargaining system. It was accepted by more moderate unions in exchange for Fiat's pledge to use it to produce its new Panda model there. FIOM, which is linked to the nation's biggest union CGIL, claimed that, among other things, the Pomigliano accord is against the Italian constitution because it infringes on workers' right to strike. Fiat said the agreement was necessary to boost productivity and make the facility viable and has introduced similar factory-specific deals at other plants in Italy.