Deutsche Bank earned itself some breathing space after a turbulent two months by posting its biggest quarterly profit in more than a year — but its chief executive warned there were more -difficult days ahead.

Germany’s biggest bank has been under intense pressure since it disclosed last month that the US justice department had demanded $14bn to resolve a probe into the alleged mis-selling of mortgage securities, prompting investor fears that Deutsche might be forced to raise capital, and unsettling the bank’s clients.

But, like many of its US peers, Deutsche fared better than expected in the three months to September, eking out a net profit of €278m. That was far better than the €6bn loss in the same quarter last year, when it took a number of goodwill writedowns, restructuring and -litigation charges, and bested the €394m net loss predicted by analysts.