A dispute over proposed pay cuts and other cost reductions at Iarnród Éireann has been referred to the Labour Court.
Last month, most unions rejected proposals negotiated at the Labour Relations Commission, which would have included pay cuts ranging from 1.7% to 6.1%.
Iarnród Éireann issued a statement saying that a Labour Court hearing will take place on 4 April.
The company said it hoped that the hearing would lead to a speedy and satisfactory resolution.
It said the savings sought were essential to secure the financial viability of Iarnród Éireann, to protect services, and ensure the security of employment of the workforce.
Iarnród Éireann also noted that every week that passed without the savings being secured was costing the company an extra €100,000.
The National Bus and Rail Union has given a guarded response to the hearing.
General Secretary Dermot O'Leary said: "The expectation that the Labour Court can bring about an Industrial Relations solution to what is a politically imposed problem runs the risk of undermining those State bodies tasked with resolving Industrial disputes".
He added: "reducing subvention to the levels which obtained in 1998 and then expect that you can maintain a 2014 level of service by simply asking workers to plug the gap is not a sustainable funding platform for public transport provision".