FRANKFURT (Reuters) -Shares of Deutsche Bank and Commerzbank opened sharply lower on Tuesday after an undisclosed investor on Monday evening sold stakes of more than 5% in Germany’s top two lenders.

The exit by the large shareholder follows a similar move by U.S. private equity firm Cerberus in recent months, and comes as both banks implement turnaround strategies to lift profitability and rebuild confidence among investors.

Deutsche Bank was down 8.2% and Commerzbank down 6.9% at the start of trade.

Deutsche said in a statement that it remained “confident in our strategy”.

“Our focused business model and risk management capabilities have proven their resilience in challenging times,” Deutsche said.

Commerzbank declined to comment.

The sale resulted in proceeds of 1.75 billion euros, based on calculations of the deal from information provided by sale’s bookrunner, Morgan Stanley.

(Reporting by Tom Sims and Alexander Huebner, editing by Kirsti Knolle and Madeline Chambers)