A rating agency says it is about to increase the marks it has assigned many U.S. health insurers but lower marks for others.

The Chicago office of Fitch Ratings has published updated rating criteria for U.S. health insurers.

The updates reflect changes the company made in its Quantitative-Insurer Financial Strength rating methods for life insurers and property-casualty insurers in 2005.

Fitch expects to publish ratings for about 220 health insurers within the next month.

About 40% of the ratings probably will change, and most of those ratings will change by 1 rating category, Fitch estimates.

Fitch predicts about 75% of the changes will be upgrades and 25% will be downgrades.

The figures given imply that roughly 66 company ratings will rise and roughly 22 will fall, according to National Underwriter calculations.