The Financial Services Union raised the ongoing strategic review of Ulster Bank here with the Minister of State at the Department of Finance during a meeting today.
The union, which represents staff at the lender, said it used the meeting with Sean Fleming to highlight the importance of the bank in relation to issues like employment and competition.
"The Minister is acutely aware of the importance of Ulster Bank to maintaining jobs and retaining competition in the marketplace," said FSU General Secretary, John O'Connell in a statement following the meeting.
"We already have the highest mortgage rates in Europe. If Ulster Bank were to exit the market, it would lead to less competition and possible higher charges."
Mr O'Connell also said that the union is concerned that if Ulster Bank were to close here, it would leave the two pillar banks exposed to a takeover, "as less competition would undoubtably make AIB and Bank of Ireland more attractive to a foreign investor."
"The Government needs to be cognisant of this. A statement from NatWest confirming its commitment to the future of Ulster Bank in the Republic of Ireland would be the best outcome for staff, customers, and competition," he said.
The union also raised its call for a banking forum to be set up which would include all stakeholders and would consider the future of the banking market here.
The Central Bank's consumer code of conduct was also discussed during the meeting, which was described by the FSU as "constructive".