Barclays' pre-tax profits have fallen 26% in Q3 as a drop in trading revenue and its ongoing restructuring programme hit growth.
The bank reported pre-tax profit, excluding gains and losses on its own debt, of £1.39bn in Q3. That was down from £1.87bn a year earlier.
Shrinking investment bank earnings were in part to blame for the drop: revenue from fixed income, currencies and commodities fell 44% to £940m, the bank said.
Elsewhere, it acknowledged it is co-operating with authorities in a wide-ranging probe into the manipulation of currency markets.
"The investigations appear to involve multiple market participants in various countries," Barclays said.
"[The bank] is reviewing its foreign exchange trading covering a several year period through August 2013 and is cooperating with the relevant authorities in their investigations."
The group's wealth and investment management division was among the areas hit by its 'transform' restructuring programme.
The division returned to profit in Q3, posting a pre-tax profit of £7m compared with a £13m loss in Q2, but adjusted profits for the first nine months of 2013 dropped from £126m to £31m as a result of restructuring charges.
Outlook for income
Chris St John to take over £3bn UK Select Opps