It cited one person as saying that Commerzbank Chief Executive Martin Zielke "would rather do it today than tomorrow", but that new Deutsche Bank CEO Christian Sewing had said internally a merger was not on the agenda in the next 18 months.

It added that Finance Minister Olaf Scholz could also imagine a deal to combine the two lenders.

"We do not comment on banks' strategic decisions," a spokeswoman for the German Finance Ministry said. The German government still owns a 15 percent stake in Commerzbank after bailing it out during the financial crisis.

Deutsche Bank and Commerzbank both declined to comment.

The news sent shares in Commerzbank as much as 4 percent higher to a four-week high at 8.74 euros.

Shares in Deutsche Bank were 0.8 percent higher at 9.66 euros by 1418 GMT, outperforming a 0.5 percent slide by Germany's blue-chip DAX index <.GDAXI>.

Deutsche Bank, which has bought German peers Postbank and Sal. Oppenheim over the last decade, also held talks with Commerzbank over a potential merger in 2016.

At the time, the two lenders shelved the project as they wanted to complete their restructuring efforts before taking any steps in the direction of a merger.

(Reporting by Maria Sheahan; Additional reporting by Michelle Martin, Andreas Framke, Hans Seidenstuecker and Andrea Lentz; Editing by Keith Weir)