ROME - UniCredit was able to buy 4.5% of Commerzbank from the German state because the government trusts the Italian bank, its CEO said in a newspaper interview, ruling out any "aggressive" moves such as an unsolicited buyout bid.

UniCredit CEO Andrea Orcel told Italian daily Il Messaggero his bank had been speaking with the German government for a while.

"This summer I've been back and forth between the seaside resort where my family was on holiday and Germany," he said.

"The German government has sold UniCredit a 4.5% stake in Commerzbank because it sees it as a reliable and suitable investor," he added.

Asked if UniCredit could launch an unsolicited tender offer to buy out other investors in Commerzbank, Orcel said: "No, it would be an aggressive move."

This month UniCredit emerged as the highest bidder in a government auction to sell 4.5% of Commerzbank. The Italian bank had already purchased a similar stake on the market and is currently the biggest private investor in Commerzbank.

The outcome of the government tender has stirred controversy in Germany. Several people with knowledge of the matter told Reuters UniCredit's move had caught German government officials off guard.

Orcel reiterated UniCredit was in no rush to raise its Commerzbank stake, though it plans to seek supervisory approval to buy up to 29.9% of the German rival.

In separate comments to German newspaper FAZ, Orcel reiterated UniCredit could also just sell its Commerzbank stake.

(Reporting by Valentina Za and Alvise Armellini; Editing by Giulia Segreti and Mark Potter)