Commerzbank has turned to Germany’s financial watchdog, BaFin, to investigate what it describes as economically irrational share sales to UniCredit, marking an escalation in the bitter battle over the Italian lender’s creeping takeover. In an internal communication seen by Bloomberg, a senior Commerzbank manager warned that a significant portion of the shares tendered into UniCredit’s current exchange offer may have come from market operators that also act as derivative counterparties to UniCredit, raising suspicions of coordinated activity designed to push the bid across a critical threshold.

UniCredit’s latest move has been methodical. Since first acquiring a 9% stake in September 2024, its chief executive Andrea Orcel has steadily built a position that now stands at a declared 26.7%, with an additional 7.6% of shares already delivered into the ongoing public exchange offer. Based on the most recent filings, the potential holding has edged above 50%, meaning control of Germany’s second-largest private bank could effectively change hands unless regulators or political forces intervene. The offer, which runs until 15 June, allows Commerzbank shareholders to swap their holdings for UniCredit stock, a ratio that for much of the tender period has made the transaction unattractive on pure financial grounds.

Viewed from Frankfurt, the German establishment’s opposition — spanning government, political parties, and trade unions — remains unwavering. The sentiment, captured in the German press as a search for “who” facilitated the share sales, reflects a broader anxiety about losing a pillar of the country’s corporate banking system to an outside player. In Milan, the manoeuvre is cast more coolly, as a rational cross-border consolidation play that would create a stronger European champion. The gap between these perspectives has only widened as UniCredit pushes forward despite Berlin’s vocal hostility.

The standoff now shifts to BaFin, which must assess whether the derivative-linked share transfers breach any market conduct or takeover rules. A finding of irregularity could, at minimum, delay UniCredit’s timetable and force a protracted legal review. Beyond the immediate regulatory question, the episode carries significant weight for the future of European banking integration. If UniCredit succeeds, it could embolden other cross-border deals; if it is blocked or forced to retreat, the signal to the market will be that national political considerations still trump the logic of a single financial market. For now, the fate of Commerzbank hangs on whether Frankfurt’s call for a probe yields results before Orcel’s tender closes.