Sick enrollees doom UnitedHealth's Obamacare business

The largest insurer in the U.S. expects to lose more money in Obamacare because enrollees were sicker this year than in previous years, a new development as other insurers plan to raise rates next year.

UnitedHealth said in an earnings call Tuesday that it has generated more losses from its Obamacare business in the second quarter of this year. It has lost about $200 million this quarter and expects to lose $600 million by the end of the year.