The chief executive of the company that owns Ulster Bank has said there will be "no big announcement" on job cuts when the company publishes its strategic review next week.
However, the union representing staff at the lender said in the long-term it was braced for "significant job losses" at the bank, which employs 6,500 in Ireland.
The bank is owned by Royal Bank of Scotland, which is reported to be preparing for a dramatic retrenchment.
The company is due to announce results and a strategic review on Thursday.
According to news agency Bloomberg, Ross McEwan, CEO Royal Bank of Scotland, emailed staff this afternoon to reassure them regarding their jobs.
He described speculation about cuts to employment as "frustrating and unsettling".
But the head of the IBOA trade union in Ireland, Larry Broderick, said the prospect of further cuts to employment in Ulster Bank, on top of 1,600 jobs already lost in the bank in the past four years, was a source of renewed fear and anxiety for these workers.
"Significant cuts to the branch network on the island of Ireland have also been mooted in some quarters, along with the outsourcing of more of the support functions based in Dublin and Belfast to Edinburgh and further afield," Mr Broderick said.
Sources suggest Ulster Bank is expected to confirm its commitment to Ireland and is likely to outline its future direction.
Mr McEwan has written to the IBOA trade union to confirm that the lender will operate in accordance of a procedural agreement that was recently concluded between the IBOA and the bank.
The agreement lays down rules for future engagement between the union and the bank.
RBS to downsize by as much as a quarter
Reports today suggested that as many as 30,000 jobs are to go at Royal Bank of Scotland over the next few years as part of plans to shrink the bailed-out bank.
The group is expected to announce an exit from many of its riskier investment bank activities, as well as much of its overseas business.
The bank, which is just over 80%-owned by the UK government, will refocus its activities on retail customers, small businesses and larger corporates.
The RBS group employs a total of 120,000 staff.