Talks between unions and management at Bus Éireann aimed at resolving the all-out strike at the company are continuing at the Workplace Relations Commission.
On Saturday, some sources close to the negotiations described the process as “very challenging”.
The strike has now been under way for 16 days.
It 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 unilaterally new cost-saving efficiency measures and work practice changes.
The company is arguing that these moves are essential in order to stave off insolvency.
However, unions at the company are concerned that the moves could result in significant reductions in staff earnings.
The talks, which have been been under way since Wednesday, are understood to be focusing on the issue of pay and earnings.
Consolidated pay
According to some sources, a new system of consolidated pay - which would bring together core salaries and premium payments for staff - has been under consideration at the talks.
Two previous rounds of talks at the Workplace Relations Commission have ended unsuccessfully.
There has been speculation in recent days that if an agreement cannot be reached in the current Workplace Relations Commission negotiations, some of the issues in the dispute could be referred to the Labour Court.
If the strike at Bus Éireann continues, it could spread to other parts of the transport system.
The trade union Siptu is currently balloting both Bus Éireann school bus staff and its Dublin Bus members for related industrial action.
