Many insurance companies are raising prices far beyond what is warranted by the impact of the Sept. 11 attacks, a consumer group said Wednesday as Congress considers legislation to provide government help for the industry.

The Consumer Federation of America also urged state insurance regulators to tighten their oversight of rates and coverage.

"Insurers are sharply and unjustifiably increasing rates" or dropping terrorism coverage, Travis Plunkett, the group's legislative director, said at a news conference. He said the legislation to aid insurance companies "would put taxpayers on the hook for billions at a time when the industry is thriving."

Robert Hunter, Consumer Federation's director of insurance, called the rate increases "a feeding frenzy." Hunter is a former Texas insurance commissioner who also directed the federal government's riot insurance program in the late 1960s.

Companies that write policies protecting property were hit hard by the assaults against the World Trade Center towers and the Pentagon, having to pay claims estimated at $40 billion to $70 billion. The industry remains healthy overall.

Hunter suggested the attacks should have led to increases of around 10 percent to 15 percent. Instead, insurers have been doubling rates or raising them even more on some commercial, industrial and airline policies, the consumer advocates said. They said the increases have come in coverage areas other than terrorism, while major reinsurance companies — which assume part of the risk covered by insurance firms — have said they won't renew terrorism coverage after Dec. 31.

An example: the annual cost of insuring Giants Stadium in New Jersey, across the Hudson River from lower Manhattan, has jumped fivefold, from around $700,000 to $3.5 million.

An insurance industry official said the higher rates don't amount to price gouging and are needed to ensure that companies have sufficient capital to cover future unforeseen events.

In addition to the impact of the terror attacks, increased insurance prices may reflect other problems, said David Snyder, assistant general counsel of the American Insurance Association.

CNA Financial Corp., the second-biggest U.S. insurer, for example, lost $155 million in the third quarter. The company attributed the losses to the Sept. 11 attacks as well as to asbestos and pollution claims it had to pay. CNA also announced Wednesday it will eliminate about 10 percent of its work force.

Consumers with home and car insurance policies shouldn't feel the pinch of rate increases, analysts say. But bigger insurance costs for businesses could lead to higher prices on some goods and services and possibly job layoffs.

Last Thursday, the House passed a version of the legislation that would commit the government, for at least a year, to covering 90 percent of losses from another major terrorist attack; insurance companies would pay the rest. The measure would require insurers to reimburse the government for a portion of the aid.

The vote was 227-193, mostly along party lines. Democrats withdrew their support after provisions limiting terrorism lawsuits, favored by President Bush and the House Republican leaders, were added to the bill. The changes could make it tougher for lawmakers to reach agreement with the Democratic-controlled Senate on compromise legislation. At least four competing bills or draft proposals have been put forward in the Senate.

The Consumer Federation officials said any legislation should prohibit insurance companies from dropping terrorism coverage. Many insurers have asked state regulators for permission to exclude terrorism coverage from policies next year.