Commerzbank escalated its dispute with shareholder UniCredit by requesting a German regulator review the Italian lender's offer support levels. The German bank's action signals mounting tension as UniCredit attempts to acquire the remaining stake in Commerzbank it doesn't already own.

The regulatory request comes with less than two weeks remaining in UniCredit's acquisition window. This move represents Commerzbank's formal pushback against the terms of the offer, suggesting significant disagreement over valuation or conditions of the proposed purchase by the Italian lender.

The timing of this regulatory intervention creates uncertainty for both banks as the acquisition deadline approaches. Market observers will watch how German authorities respond, potentially affecting the deal's structure, timeline, or even its feasibility if regulators find issues with the offer's support mechanisms.