Talks to resolve the all-out strike at Bus Éireann have been adjourned until Saturday.
Sources on Friday described the process at the Workplace Relations Commission as "slow".
The strike has brought all Bus Éireann services, with the exception of school transport, to a halt.
The dispute centres on moves by management at the State-owned transport company to introduce cost-saving efficiency measures and work practice reforms without agreement with unions.
Unions are concerned the management plans will result in significant loss of earnings for members, claiming Bus Éireann drivers would lose up to €300 per week in earnings.
Management argues the measures are essential to stave off impending insolvency, warning that the company could run out of money next month.