Royal Bank of Scotland has put aside £856m ($1.3bn, €1.2bn) to cover charges relating to previous misconduct at the bank, pushing the majority state-owned lender to a loss of $446m in the first quarter of 2015.
RBS set aside £334m for charges relating to the alleged manipulation of foreign exchange rates, £100m relating to compensation for mis-selling loan insurance and a further £257m for other customer compensation.
The bank said in a statement it was progressing towards its 2015 targets and establishing a "stronger, simpler" business.
The UK government owns 80% of the bank, after it was bailed out in 2008 at the height of the global financial crisis.
RBS reported an attributable loss of $446m for the first three months of the calendar year.
It also reported an underlying operating profit of £1.63bn, 16% higher than the £1.28bn it made during the same period last in 2014.