March 25 (Bloomberg) — Two months before health insurers must submit rate proposals for 2015 to government regulators, WellPoint Inc. fired a surprising shot across their bow by predicting it may ask for "double-digit-plus" increases.

Kathleen Sebelius, the U.S. Health and Human Services secretary, said March 13 that while premiums for health plans sold on the Obamacare insurance exchanges would rise next year, the increases would be "far less significant than they were before the passage of the Affordable Care Act."

Individuals who bought their own insurance in 2010 paid 13 percent more than in 2009, a Kaiser Family Foundation survey found. The exchanges, which opened in October, serve those who buy their own individual or family insurance and aren't covered by employer or government health plans. WellPoint's statement on next year's rates, the first by an insurer, startled some analysts while others said the company may be hedging bets as the Obama administration continually changes the rules on the Patient Protection and Affordable Care Act.