Feb. 7 (Bloomberg) -- Deutsche Bank AG Chief Executive Officer Josef Ackermann said rating downgrades for bond insurers pose risks that could match the U.S. subprime market collapse.

``It could be a tsunami-like event comparable to subprime,'' Ackermann said in a Bloomberg Television interview in Frankfurt today. Deutsche Bank, Germany's biggest bank, is ``well positioned'' on its risk from bond insurers, he said.

Bond investors stand to lose $200 billion should MBIA Inc., Ambac Financial Group Inc. and Financial Guaranty Insurance Co. forfeit their AAA grades because of declines in mortgage-backed securities they insure, according to data compiled by Bloomberg. Ratings on $2.4 trillion of debt that the industry guarantees would be thrown into doubt.

Banks and securities firms have already reported credit losses and writedowns of $146 billion. Downgrades of the bond insurers may force financial firms to write down a further $70 billion, Oppenheimer & Co. analyst Meredith Whitney said last month.

Ackermann made his comments on the day Deutsche Bank said fourth-quarter profit fell 48 percent, less than analysts estimated, to 953 million euros ($1.39 billion) as it avoided the collapse of the U.S. subprime mortgage market. The shares rose 0.4 percent to 75.27 euros in Frankfurt, valuing the bank at 40 billion euros.

JPMorgan Chase & Co. Chief Executive Officer Jamie Dimon said the third-largest U.S. bank may lose $200 million if bond insurers have their credit ratings lowered, at a conference today in Naples, Florida.

MBIA Share Sale

Bond insurers led by MBIA are trying to bolster their capital in an attempt to salvage AAA grades. Armonk, New York-based MBIA said yesterday it plans to sell $750 million of stock, with private-equity firm Warburg Pincus making up any shortfall in the sale by buying convertible participating stock.

The extra funds may not be enough to avert a downgrade because rating companies are increasing the capital they demand bond insurers set aside, Bank of America Corp. analysts led by Jeffrey Rosenberg wrote in a note yesterday.

Fitch Ratings said this week it may cut MBIA's AAA insurance ranking, after lowering New York-based Ambac's unit by two levels to AA last month because of mounting losses on subprime-related debt.

Bailout Efforts

New York Insurance Superintendent Eric Dinallo is trying to organize a bank-led rescue of some of the insurers. Eight banks including New York-based Citigroup Inc. and UBS AG in Zurich are working on financing for Ambac, a person briefed on the plan said last week.

Credit Agricole SA's Paris-based Calyon unit is leading talks to bail out New York-based Financial Guaranty Insurance Co., the third-biggest U.S. municipal bond insurer, the Wall Street Journal reported yesterday, citing people familiar with the situation.

The bailouts should be allowed to fail, hedge fund manager William Ackman said in a letter to Federal Reserve Chairman Ben S. Bernanke. Ackman is a managing partner of hedge fund Pershing Square Capital Management LP, which is trying to profit from declines in the stock and bonds of MBIA and Ambac.

``It is bad practice to rely on the judgment of those whose misjudgments have caused the current crisis,'' Ackman wrote in the letter dated Feb. 5.

European Central Bank President Jean-Claude Trichet rejected Ackermann's characterization of the potential fallout from bond insurer downgrades.

``I certainly would not mention anything like waves of tsunami or any other mention of that sort,'' Trichet said at a press conference in Frankfurt. ``The fact that this correction continues along various markets is not something which should surprise us, its an ongoing process.''

To contact the reporter on this story: Aaron Kirchfeld in Frankfurt at akirchfeld@bloomberg.net

Last Updated: February 7, 2008 12:26 EST