SCOR also said that a retraction from the health reinsurance sector, which it began in the United States earlier this year, is now being extended to the rest of the world.

Explaining the loss estimate, SCOR said that large loss notices in the fourth quarter, excluding World Trade Center losses, exceeded total losses in this category for the first nine months.

The company also said that claims experience from earlier underwriting years is running off higher than expected and that the failure of financial markets to recover has led the company to adjust investment results.

A.M. Best in Oldwick, N.J. and Standard & Poor's in New York both downgraded their ratings of SCOR yesterday.

A.M. Best lowered the financial strength ratings of SCOR and its reinsurance and insurance subsidiaries to "A" (excellent) from "A-plus" (superior) and removed the rating from under review.

S&P dropped the financial strength ratings to "single-A-plus" from "double-A-minus" for all subsidiaries except one. U.S. insurer Fulcrum Insurance Co. remains at "single-A."

In its rating announcement, S&P called SCOR's loss estimate "unexpected," saying that it "puts into question the company's control over some underwriting areas."