Commerzbank returned to profit in the fourth quarter as provisions for bad loans fell thanks to Germany's robust economy, allowing it to draw a line under a six-year restructuring by announcing to close its 'bad bank' comprising non-core assets.

Germany's second biggest lender said on Friday it posted a quarterly net profit of 187 million euros ($211 million), in line with expectations, after it lost 280 million euros in the year-earlier period.