Ulster Bank plans to close 11 branches in Northern Ireland in the first half of next year, reducing its network to 44 locations.
The lender, a unit of Royal Bank of Scotland (RBS), will seek to cut 40 roles on a voluntary basis.
"Banking has changed radically in recent years. More and more of our customers are using digital technology and fewer are using our branch network," said Sean Murphy, managing director of personal banking at Ulster Bank in Northern Ireland.
“While we continue to keep our network under review in response to changing customer demand, we still have Northern Ireland’s largest bank branch network.”
Ulster Bank had 85 branches in Northern Ireland in 2009 before lenders across the industry started to slash costs during the financial crisis. Ulster Bank in the Republic closed 22 branches this year, reducing its network to 88.
The lender had 190 locations across the Republic before the crisis, including branches that carried the First Active brand, which was axed in 2010.
“Ulster Bank should immediately publish its impact assessment reports on the closures this year and, at the very least, put in place additional mobile banks for the areas worst hit,” said Larry Broderick, general secretary of the Financial Services Union.
“I will be writing to Ulster Bank and its parent RBS demanding that it gives, at a minimum, a three-year commitment to retain its remaining branch network.”