Banks cite risks of getting deal done, restructuring costs.
The announcement came during the sixth week of talks.
The news raises questions about the future of both banks.
Deutsche shares rose 1.1pc; Commerzbank shares fell 2.6pc.
Frankfurt | German hopes of creating a national banking champion able to challenge global competitors collapsed on Thursday (Friday AEST) when Deutsche Bank and Commerzbank ended merger talks because of the risks of doing a deal, restructuring costs and capital demands.
Germany's two largest banks announced that nearly six weeks of high-level negotiations about a tie-up had ended in failure, confirming an earlier Reuters report and immediately raising questions about the future of the Frankfurt-based rivals.
