By Tom Sims, Andreas Rinke and Valentina Za

FRANKFURT (Reuters) -The CEO of UniCredit renewed his push to merge the Italian bank with its German rival Commerzbank , attempting to make his case in a letter to Germany's Chancellor Friedrich Merz.

UniCredit last year acquired a large stake in the German lender and has been calling for a full takeover, despite resistance from Commerzbank management and the German government, which is another top shareholder.

"As I have repeatedly said, I would like to sit around a table and discuss this matter face-to-face," UniCredit Chief Executive Officer Andrea Orcel wrote in the June 18 letter to Merz, according to a copy seen by Reuters. 

Sueddeutsche Zeitung first reported the existence and content of the letter, which was also sent to German Finance Minister Lars Klingbeil.

Both Merz and Klingbeil have voiced opposition to any tie-up of the two European banks.

"It would create a new national banking champion for Germany - an institution dedicated to supporting the revitalisation of the German economy that is at the heart of the new government's agenda," Orcel wrote, in reference to a possible merger.

"While we firmly believe a merger would be the optimal eventual direction of travel, should this not be feasible, then there is still a need for us to sit together to find a mutually agreeable and positive solution that works for all parties," he wrote. 

The UniCredit CEO noted that German politicians would have the final say on the location of the headquarters of a combined bank. A merger would bring together Frankfurt-based Commerzbank and UniCredit's German unit, Munich-based HVB.

"We fully recognise the sensitivities connected to this issue ... the eventual location of a combined entity headquarters would be at the discretion of the German government and respective mayors," he said.

Orcel also said Commerzbank's branch network would be protected and that local decision-making would remain for things like loans.

"The principle of local, market-centric decision-making is central to our culture and would continue to be guaranteed," Orcel wrote.

UniCredit wasn't immediately available for comment. Commerzbank declined to comment.

Germany's finance ministry confirmed receipt of the letter. Klingbeil wrote back to express his thanks and referred Orcel to Commerzbank's management, it said.

In May, Commerzbank CEO Bettina Orlopp, who has been working on keeping the bank independent, said "we don't need constant interference from the outside".

(Additional reporting by Kirsti Knolle, Editing by Thomas Seythal, Mark Porter and Paul Simao)