German banks may face further write-downs given the difficult market situation, Deutsche Bank Chief Executive Josef Ackermann told Germany's Bild newspaper in an interview published on Monday.
Ackermann told the paper that it would probably take another six to nine months for the financial crisis to pass.
Asked whether German banks would need to make further write-downs, Ackermann said: "You can't exclude it given the continuing difficult markets."
Banks around the world have been forced to write down the value of their holdings of loan packages and other financial instruments after the market for risky mortgages in the United States turned sour.
Ackermann did not say in the interview whether further write-downs would be needed at Germany's biggest bank.
He said he did not expect the current financial problems to develop into an economic crisis.
The United States were boosting its economy with fiscal programmes and interest rate cuts, while growth in Europe and developing countries remained robust, he said.
"Global growth will slow, but we are a long way from a world economic crisis," he said, adding that he also did not expect a stock market crash.
Ackermann repeated that Deutsche Bank is checking its risk control systems to ensure that there could be no trading scandal of the type that has rocked French bank Societe Generale, where a junior trader ran up billions of euros in losses. A report would be ready within weeks, Ackermann said.