According to the lender, the decision has been made because it does not believe Ulster Bank in the Republic of Ireland will be in a position to achieve an acceptable level of sustainable returns.
NatWest has confirmed that it will begin to withdraw from the country, where it uses the Ulster Bank brand.
It has over 2,800 staff based in the Republic of Ireland, however, NatWest has said that it will attempt to keep job losses to a minimum.
Overall, Ulster Bank controls an estimated 15% of the Irish mortgage market and its total loan book equates to €20.5bn.
The firm, which is the third largest lender in Ireland and has 110 branches, has outlined that it expects its Northern Ireland operation to be unaffected.
Alison Rose, chief executive of NatWest Group, said: “In recent years, our strategy for Ulster Bank in the Republic of Ireland has been to improve returns by growing the business, reducing costs and resolving legacy issues.
“ I want to pay tribute to our colleagues who through their commitment and dedication have helped to transform this business.
“Our priority over the coming months will remain on supporting our customers, communities and colleagues through these difficult times.
“Following an extensive review and despite the progress that has been made, it has become clear Ulster Bank will not be able to generate sustainable long terms returns for our shareholders.
“As a result, we are to begin a phased withdrawal from the Republic of Ireland over the coming years which will be undertaken with careful consideration of the impact on customers and our colleagues.”
