"I would strongly advise against creating an even larger national champion," she said, adding that cost savings would probably not be easy to achieve, it was not clear the deal would make business sense and that it would exacerbate the "implicit state guarantee".

(Reporting by Klaus Lauer and Reinhard Becker; Writing by Paul Carrel; Editing by Madeline Chambers)

Stocks treated in this article : Deutsche Bank, Commerzbank