Ulster Bank has reported an operating profit of €362m for last year, down sharply from the figure of €606m in 2014.
The bank had received a boost last year as it released impairment provisions - money previously written down in anticipation of losses which have now been written back and which goes straight to the bank's bottom line.
Ulster Bank said its impairment releases of €194m, although at lower levels than 2014, continued to reflect the improving economic conditions.
The bank, which is owned by Royal Bank of Scotland, said that its total income for the year rose to €758m in 2015 from €749m the previous year.
It said its operating expenses rose to €590m from €523m due to higher pension, litigation and regulatory charges as well as the impact of a weakening euro on its sterling cost base.
It also said that further cost savings were seen last year which reflected its ongoing cost reduction programme.
New lending to business increased by 65% to €1.5 billion during the year, while mortgage drawdowns rose by 53% to €0.7 billion.
"2015 has been another solid year for Ulster Bank with an operating profit of €362m representing two years in profit for the Bank in the Republic of Ireland," commented the bank's interim chief executive Paul Stanley.
Mr Stanley said the bank has seen a strong start to 2016 and is confident in its outlook.
He added that Ulster Bank continues to the support of its parent, RBS.