ING Groep has approached Commerzbank bout a possible tie-up, a German magazine has reported.
Manager Magazin, citing unnamed sources, said ING made the approach to the German government, which owns a stake in the German lender, and to Commerzbank chief executive Martin Zielke.
But Zielke declined to engage in formal talks, the report said.
The reported interest by ING comes as Commerzbank and Deutsche Bank engage in talks to merge.
According to the magazine, ING's CEO Ralph Hamers suggested moving ING's headquarters to Frankfurt in event of a deal.
He also promised to cut fewer jobs than would be the case in a Commerzbank tie-up with Deutsche, the magazine said.
Commerzbank is a ripe candidate for a foreign takeover, which is one reason why the German government has been encouraging a tie-up with Deutsche to create a national champion, sources have told Reuters.
Italy's UniCredit has said it could explore a merger with Commerzbank if talks with Deutsche fail, two people with knowledge of the matter told Reuters earlier this month.