FRANKFURT - Italy's UniCredit bought a stake of nearly 4.5% in Germany's Commerzbank that was sold by the German government, the German government's finance agency announced on Wednesday.

The purchase for 702 million euros ($775 million) makes UniCredit one of Commerzbank's largest shareholders and follows speculation in recent years that the Italian lender could be interested in taking over the German bank.

The purchase of the Commerzbank shares by a single buyer is a surprise. It had been expected to go to multiple institutional investors in smaller blocks.

UniCredit paid 13.20 euros per share, higher than the daily closing price of 12.60 euros, Germany's finance agency said.

Shares in Commerzbank rose 4.4% in premarket trade.

Neither UniCredit or Commerzbank was immediately available for comment.

UniCredit, which is already present in Germany through HVB, reportedly discussed merging with Commerzbank before Russia invaded Ukraine in 2022.

(Reporting by Tom Sims, Christian Kraemer, and Giulia Segreti, Editing by Rachel More and Christina Fincher)