A more than 20-fold rise in equity revenues helped support the earnings of the investment banking arm of BNP Paribas, as the French bank stuck to a rigorous cost cutting programme, which took the division's expenses-to-revenues ratio to a record low.

The costs-to-revenues ratio of the corporate and investment banking division, much of which is based on staff salaries and bonuses, fell to 43.8% in the second quarter, its lowest level on record, according to BNP Paribas.