SIPTU has confirmed that talks with Aer Lingus' negotiating team have been deferred due to the late hours worked last night.
The board of Aer Lingus had concluded its discussions on cost saving proposals at the airline.
A spokesperson for Aer Lingus said the board recognises the very real progress achieved with cabin crew but said that a significant gap remained with the pilots.
There are no further talks planned with the pilots' representatives at this stage.
The airline said the pilots were not offering any sustainable options for real costs savings.
The IMPACT union had put forward its proposal to Aer Lingus on achieving cost-cutting measures thought to be in the region of €20m.
Negotiations between the airline and unions had gone on until the early hours of this morning.
Cabin crew representatives left the Labour Relations Commission at 1.30am this morning.
It is understood the Irish Airline Pilots' Association, the union representing pilots, remained at the talks until 5am.
SIPTU expects to return to the LRC on Monday to continue negotiations.
