Anglo Irish Bank is to start a consultation with staff that will see up to 350 being made redundant by the end of 2012, 130 of which will come from Ireland.
In a statement the bank said it hoped to achieve the workforce reduction through voluntary redundancies.
However, it accepted compulsory lay-offs could be required if targets are not met.
The bank said the measure was part of a process to wind down the bank by 2020.
It said it had held a series of face-to-face briefings with employees today and that no redundancies would take place until the consultation process had been completed.
Anglo recently merged with Irish Nationwide as part of the Government's banking strategy.
IBOA General Secretary Larry Broderick said the IBOA was disappointed, though not surprised, at the announcement.
'While we acknowledge that the Bank has indicated its preference that redundancies should be implemented on a voluntary basis, IBOA will urge management to strengthen that commitment so as to avoid making any staff redundant on a compulsory basis given the current employment situation in the financial services sector.' he said.
'Negotiations on other issues such as the level of the severance terms and the criteria for selection will also begin tomorrow. As part of the restructuring agenda, we also intend to raise the concerns of the staff who will remain with the bank on issues such as redeployment, retraining and remuneration.
'Our aim is to achieve a fair and balanced approach to the restructuring of the business both for those staff who opt to leave the bank at this time and for those who decide to remain with the bank,' said Mr Broderick.
