Deutsche Bank's chief executive declared the bank has “shown its strength” during the credit crunch of the past year, as losses from corporate banking and securities narrowed and the group returned to the black in the second quarter.

Deutsche Bank made a €311m ($485m) pre-tax loss in its corporate banking and securities business, compared with a €1.8bn profit in the second quarter last year, as it wrote down €2.3bn on mortgage-backed securities, monoline insurers, commercial real estate and leveraged finance instruments. The bank revealed the figures in its second-quarter results statement today.