Aer Lingus management and unions are attempting to reach agreement on a €20m cost-cutting programme.
Last week, the airline warned pilots and cabin crew that if they failed to reach agreement on cost cuts by today they would have to forego wage increases due under the national wage agreement.
With sources describing talks as being at a delicate stage, both the company and unions accept that today's deadline is unlikely to be met.
Last year, Aer Lingus Chief Executive Dermot Mannion promised shareholders he would deliver PCI07, a €20m programme of savings on staff costs. However, he has still failed to reach agreement with unions.
Last December the national implementation body devised a schedule of negotiations, after several strike threats.
SIPTU has said it is optimistic that the proposal on cutting staff costs can be finalised by the end of next week. This afternoon, an agreement was reached on standardising the core working week at 35 hours and 50 minutes for many SIPTU members.
SIPTU says other issues still must be finalised, including rosters and the lenght of shifts.
