Bondholders received 1.20 percentage points more than on bonds with the lowest investment rating, Baa.

But he said that "it doesn't make intellectual sense to have an investment rating unless you have some sort of price target in mind."

The company's slide was touched off when Bear Stearns cut its investment rating for the company from "buy" to "hold."

Bonds, at least those that carry a high investment rating, used to trade calmly and quietly.

The credit rating agencies granted these securities safe investment ratings, which facilitated their sale to investors around the globe.

Mr. Healy did not change his investment rating of the company, he said, because he had already rated it a "hold."

The investment bankers counter that lining up loans to companies without investment ratings is just an extension of their current business.

An investment rating of a real estate property measures the property's risk-adjusted returns, relative to a completely risk-free asset.

And there were the drug stocks, which continued the slide they began on Thursday after an analyst cut her investment rating of 12 of them.

Securities with the highest investment ratings have borrowing costs of 9 to 10 percent.