Commerzbank beat quarterly profit forecasts today, but the German lender said it needed to do more to get back to sustainable growth. 

"We cannot yet be satisfied with the quality of our earnings," the bank's chief executive Martin Zielke said in a statement. 

Germany's second-largest lender behind Deutsche Bank reported a fourth-quarter net profit of €183m, beating analysts' average forecast for €154m. 

Revenues were flat at €1.3 billion, in line with expectations, held back by low interest rates and weak loan demand from German companies. 

Commerzbank did not provide guidance for 2017 earnings but said it aimed to keep its cost base stable. 

It expects to set aside the same amount of money as in 2016 to cover bad loans at its retail and corporate bank, but sees provisions for bad shipping loans rising to €450-600m. 

In 2016, it hiked group provisions by a third to €900m, mainly due to its shipping industry exposure. 

In a sign of the crisis being suffered by shipping firms due to a glut of vessels and sluggish global trade, the world's largest container shipping group Maersk reported a $2.7 billion quarterly loss earlier this week. 

Operating earnings at Commerzbank's cash cow Mittelstandsbank unit, which caters to the German economy's backbone of small and medium-sized companies, were up quarter-on-quarter as provisions fell. 

The retail bank saw flat operating profit due to pressure on its deposits business, where negative interest rates weighed, despite cost cuts and higher customer demand for mortgages. 

The bank announced in September it would cut more than a fifth of its workforce and suspend its dividend as it tackles the challenges of weak profits and a shift to online banking.