The pace of profit growth at Barclays' investment bank slowed in the third quarter despite higher revenues across most of the unit's businesses, as slightly higher costs took their toll on the bottom line.

The UK bank, in its third-quarter results on October 29 - the day after it confirmed that former JP Morgan investment bank and asset management chief JesStaley would become its next chief executive in December - said that third-quarter pre-tax profits at its investment bank were 12% higher than the year-earlier period at £317 million.