UnitedHealth Group Inc., the biggest U.S. health insurer, provided a forecast for profit next year that was below analyst estimates as the company prepares for a poor business environment and reductions in government revenue.

Earnings in 2013 will be $5.25 to $5.50 a share, while revenue will be $123 billion to $124 billion, the Minnetonka, Minnesota-based company said today in a filing with the Securities and Exchange Commission. Analysts anticipated $5.58 a share and $119.4 billion, based on the average estimates compiled by Bloomberg. UnitedHealth will hold its annual investor conference tomorrow to discuss the company’s outlook.