Commerzbank shares jump 17% after Unicredit buys 4.5% stake from the German government

Commerzbank shares jumped on market open on Wednesday, after Italian bank UniCredit acquired a 4.5% stake in the Frankfurt-based lender from the German government.

Commerzbank stock was up 18% at 8:21 a.m. London time.

The stake acquisition marks the first step in Berlin's exit from its position in the German lender. The German government said it had sold around 53.1 million shares — or a roughly 4.49% tranche out of its 16.49% total shareholding — in Commerzbank for roughly 702 million euros ($775 million) to UniCredit.

Even at a reduced 12% position, the German government said it remains Commerzbank's largest shareholder.

"Commerzbank has shown that it is once again standing on its own two feet. With this the first partial sale of the investment will mark the completion of the successful stabilization of the investment Bank and thus the federal government's exit," said Eva Grunwald, managing director of the federal finance agency.

This breaking news story is being updated.