The number of owner occupier mortgages in arrears for over 90 days rose to 7% at the end of June, up by 1.4% since the end of last year.
The news was revealed after Bank of Ireland announced pre-tax losses of €1.25 billion for the first half of 2012.
Despite the increase in the number falling into mortgage arrears, Bank of Ireland said that due to some stabilization in the economy and through its own initiatives, the rate of increase reduced during the first half of the year.
Despite the rate of arrears increasing, it remains well below the industry average of 10.3% at the end of March, according to Central Bank statistics.
The level of arrears among properties bought by investors to rent out, the most distressed part of the bank's mortgage books, was 14%, up from 10.8% in December.
