Permanent TSB has said that it has briefed staff on restructuring plans, designed, the company says to create a "smaller, profitable" bank by 2016.
The banks will see the equivalent of 250 less staff, along with a drop of 10% in operating costs. The job losses will be voluntary and workers will be paid three weeks pay for every year of service.
The bank will close 16 of the current 92 branches, 2 further branches will become self-service locations.
A further Dublin city branch will close as part of creating a flagship city centre site.
The bank will have three units; permanent tsb, asset management unit and its UK mortgage loan business termed CHL.
The bank intends to re-organise the bank's head office, and it says, invest in online services.
Jeremy Masding, CEO, said that the bank wanted to minimise losses and concentrate on the core banking business, while protecting the taxpayer's investment in the group.
The Unite trade union which represents the majority of workers at Permanent TSB will meet with staff in the coming weeks.
The union says between 120 and 150 jobs are to go across the branch network and a further 75 to 100 from a restructuring of head office functions.
Staff at each of the banks locations will be briefed by management tomorrow.
No details have yet been released on which branches are to close.
"This is a very difficult time for all staff," said Unite national co-ordinator Walter Cullen.
"There is an undertaking that the jobs lost will be so on a voluntary redundancy basis but clearly there may be issues involving redeployment of those staff whose branch may close but who wish to stay within the group," he added.
