BERLIN, June 10 (Reuters) - German Chancellor Friedrich

Merz has told staff at Commerzbank he opposes Italian

lender UniCredit's efforts to build up a stake in the

bank, in a letter which Germany's finance minister said was "an

important signal" about the government's stance.

Merz addressed labour representatives at Commerzbank in a

letter dated May 26, and posted on LinkedIn on Tuesday, saying

the Italian lender's approach for Germany's second-biggest bank

was unacceptable.

"This is particularly true when it comes to a systemically

important bank such as Commerzbank AG," wrote Merz, who has

previously spoken out against a potential takeover attempt by

UniCredit, which he has said would be devastating for Germany,

with "a significant impact" on medium-sized businesses and

export financing that rely heavily on bank lending.

"I am very grateful that the chancellor has spoken out,"

German Finance Minister Lars Klingbeil said at a press

conference with his Swedish counterpart, Elisabeth Svantesson,

in Berlin.

UniCredit disclosed last year that it had built a web of

financial transactions through derivatives to secure a

Commerzbank stake of around 28%, and in March this year it

received European Central Bank approval to get to 29.9%. Under

German rules, crossing the 30% threshold triggers a buyout

offer.

UniCredit has said the stake is a financial investment and

pushed back any decision on a full takeover, which it says would

be the best outcome, to 2026-2027.

"I recognise that the political statement of a chancellor

alone is also an important political signal," said Klingbeil.

"However, we are also engaged in political discussions. As

soon as there are results, they will be made public," he added.

Politicians in Berlin fear losing one of Germany's few

remaining big commercial banks as well as tying their country's

fortunes to those of debt-laden Italy.