AIB has informed 73 back office staff that they will be transferring to services company HCL under the terms of a new outsourcing agreement.
The affected staff are primarily based in Dublin and Belfast.
In a statement, the bank said the decision had been taken as part of its overall strategy of introducing 'new productivity tools on the most commercial terms.'
It says the organisation is seeking to deliver better technology offerings for customers as it attempts to return to full sustainability over time.
In a statement the Irish Bank Officials Association said it was "extremely disappointed" that the bank had not engaged with the union before agreeing to outsource the work.
AIB said the outsourcing of certain functions would be considered where it makes commercial sense to do so both in terms of reducing costs and in enabling the business strategy.