Fresh talks to try to avert the Bus Éireann strike threatened for Monday are planned for the Workplace Relations Commission tomorrow.
The National Bus and Rail Union has said it will "engage separately with the commission" to see if there is a basis towards achieving a resolution.
The risk of an all-out indefinite strike at the company remains if management proceeds to implement planned cost reduction measures on 20 February without agreement.
SIPTU has confirmed it will also be at WRC tomorrow for talks, but spokesman Willie Noone said union representatives will meet WRC officials but not with the company at this stage.
They are due to go in at 3.30pm after they have attended the Oireachtas Committee on Transport at 1.30pm.