Italian lender UniCredit said on Monday it made a 35-billion-euro ($40 billion) takeover offer for Germany's Commerzbank, a move likely to provoke fierce resistance from the government in Berlin.

While stressing that it did not expect to take full control, UniCredit said it would raise its stake in the German bank to more than 30%, triggering a mandatory takeover offer for the whole bank under German law.

"It is expected that UniCredit will achieve a stake in Commerzbank in excess of 30% without reaching control," the Italian lender said.

"This would both remove the need for UniCredit to continuously adjust its stake to remain under the 30% threshold and an ability to increase its stake freely," it added.

UniCredit currently has a direct stake of around 26% in Commerzbank and an additional holding of some 4% through financial derivatives.

Commerzbank has made clear that UniCredit's advances are unwelcome and the German government has repeatedly voiced its opposition to a takeover.

In May, Chancellor Friedrich Merz told Commerzbank's employees in a letter that UniCredit's moves were "unacceptable."

Berlin still holds a 12.1% stake in Commerzbank, the legacy of a 2008 bailout during the global financial crisis.