California regulators seek up to $9.9 billion in fines from PacifiCare

California regulators are seeking fines of up to $9.9 billion from health insurer PacifiCare over allegations that it repeatedly mismanaged medical claims, lost thousands of patient documents, failed to pay doctors what they were owed and ignored calls to fix the problems.

In court filings and other documents, the California Department of Insurance says PacifiCare violated state law nearly 1 million times from 2006 to 2008 after it was purchased by UnitedHealth Group Inc., the nation's largest health insurance company by revenue.

Regulators said the companies broke promises to maintain smooth operations for 130,000 of PacifiCare's customers, resulting in what insurance officials nationwide believe is the largest fine ever sought against a U.S. health insurer.