The Teamsters union that represents U.S. workers at United Parcel Service on Thursday said it would respond to the firing of about 35 newly organized workers at the delivery company by filing unfair labor practice charges and potentially striking. The roughly three dozen affected specialist and administrative workers at UPS's Centennial hub in Louisville, Kentucky, organized with Teamsters Local 89 this autumn, the union said. International Brotherhood of Teamsters General President Sean O'Brien in a statement said that UPS laid off those workers despite the ruling of an independent arbitrator and falsely claimed that their work should be performed by management.