Ulster Bank's operating profit for the first half of 2016 has shown a 17% decline in the same period last year - it came to £122m (€143.8m).
It reported a net decrease in the value of its stated capital of £27m.
During the second quarter, Ulster Bank set aside a €118m provision linked to a on-going tracker mortgage investigation.
It experienced a 47% in mortgage drawdowns as it grew its market share to 18%.
Its parent company, Royal Bank of Scotland (RBS) reported a £2bn (€2.3bn) loss.
Chief executive, Ross McEwan said that this shortfall was due to "legacy issues." These include restructuring and legal costs.
He added that the bank is making progress dealing with these issues.
Mr McEwan said that the bank is now well-positioned to deal with a potential economic slowdown:
"We are clearly in phase two of our strategy, where our focus is on drawing a line under many of the legacy issues that have plagued this bank, and transforming the core business so we can deliver consistent, sustainable profits and results for our shareholders and do great things for our customers."
