The CIE unions have been invited to talks at the Labour Court next Friday.
Most of the unions are currently balloting members for strike action over a refusal of the company to pay the latest increase due to 10,700 employees under the Programme for Competitiveness and Work.
One union, the National Bus and Rail Union, has voted by more than nine to one for strike action from December 6th.
The company wants payment of the 2.5 per cent PCW increase deferred until March 31st. It also wants the payment tied to the unions agreeing to a £44 million cost cutting viability plan.
