A report by the Department of Health and Human Services said: These massive increases are disturbing examples of the problems that make reforming our health insurance system more important than ever.

The report came as President Barack Obama tries to revive stalled healthcare reform plans in the face of Republican opposition and public skepticism.

Health Secretary Kathleen Sebelius two weeks ago demanded Anthem Blue Cross of California, a unit of Wellpoint Inc, provide information about plans to boost premiums by up to 39 percent.

On Thursday, she said the agency's report showed other insurers also were seeking extreme premium increases while Americans struggled through an economic downturn. We know that insurance companies are not suffering that same kind of downturn, she said at a news conference.

Profits for the 10 largest insurance companies rose 250 percent from 2000 to 2009, 10 times faster than inflation, the report said.

The top five -- WellPoint, UnitedHealth Group Inc, Cigna Corp, Aetna Inc and Humana Inc -- took combined profits of $12.2 billion, up 56 percent from 2008, it said.

The chief executives of the top five received $24 million on average in 2008, the report said.

Robert Zirkelbach, a spokesman for the health insurance industry's trade group, blamed the soaring cost of medical care for driving the increase in premiums, saying the percentage of premiums going toward administrative costs and profits had declined.

Healthcare spending in the United States is about $2.3 trillion annually, or about 16 percent of the U.S. economy. Despite the high spending levels, some 46 million people living in the United States are uninsured.

HEALTHCARE REFORM EFFORT

Work on healthcare reform, Obama's top domestic priority last year, ground to a halt in the Democratic-controlled Congress last month.

The House of Representatives and the Senate had passed different versions of healthcare reform and were trying to reconcile the bills when Democrats lost the Massachusetts Senate seat previously held by Edward Kennedy, who died last year. That gave rival Republicans the ability to use procedural hurdles to block legislation.

Obama has invited Democratic and Republican lawmakers to a February 25 healthcare conference and promised to release a proposal for a legislative overhaul by then.

The idea is that it will take some of the best ideas and put them into a framework moving forward, Sebelius said of Obama's proposal.

The Democrats' attacks on insurers escalated after the Los Angeles Times reported in early February that Anthem Blue Cross planned to increase individual market premiums by up to 39 percent in the coming month. After Sebelius challenged the decision, the company delayed the move for two months.

The HHS report said several companies planned of had implemented big premium hikes in recent years. Anthem sought them in several different Northeastern states while Blue Cross/Blue Shield of Michigan wanted a 56 percent increase for plans sold on the individual market.

UnitedHealth, Tufts and Blue Cross asked for 13-to-16-percent increases in Rhode Island, and some plans in the individual market in Washington increased premiums by 40 percent until the state imposed stiffer regulations.

Leading experts have predicted that without reform, these increases will continue, the report said, and the federal government and most states don't have the legal authority to block or reduce health insurance rate increases.

Democrats hope highlighting the rate hikes will help boost the prospects for healthcare legislation.

The premium increases are a powerful reminder that the healthcare problems are not going away, David Kendall a senior analyst for health policy at the Third Way, a centrist think tank, said of the HHS report.

Republican Representative Dave Camp called the reported increases unacceptable but added the reforms Democrats in Congress are pursuing would actually make the current situation worse by making coverage more expensive.

The House Energy and Commerce Committee has called Wellpoint Chief Executive Angela Braly to testify about the proposed rate hikes in California at a hearing next week.

On Thursday, the committee wrote to Braly asking him to explain a seeming conflict between Wellpoint's public explanation and company data.

Wellpoint has attributed the increases in part to healthy people dropping coverage in the recession. But data the company gave to the National Association of Insurance Commissioners showed enrollment in the individual market in California appears to have increased significantly, the letter said.

WellPoint, in a statement, said the letter mischaracterizes membership data. Anthem Blue Cross of California individual membership declined by about 25,000 members between 2008 and 2009, WellPoint said.