President Obama called on Tuesday for repealing the health insurance industry’s exemption from federal antitrust laws, escalating his attack on insurers as he tries to revive his stalled effort to overhaul the nation’s health care system.

The White House sent Congress a statement throwing its weight behind a House bill to overturn parts of the McCarran-Ferguson Act of 1945, which granted insurance companies broad protection from federal monopoly oversight and left regulation of the industry largely to state governments.

The president’s move came a day after he proposed a new effort to crack down on insurers that are raising premium rates dramatically, part of a comprehensive health care plan that he posted on the White House Web site before a bipartisan summit meeting on Thursday. But the antitrust repeal was not included in Mr. Obama’s overall plan on Monday; it was instead left to the separate House legislation.

“Removing this exemption will allow appropriate enforcement and examination of potential policies that might prove uncompetitive, might stifle competition,” said Robert Gibbs, the White House press secretary. “And we think this better promotes affordability and innovation through greater choice and less market concentration.”

The proposed repeal has strong support among House Democrats, who included a version of it in the broader health care bill passed by the House last year. But the fate of the repeal remains uncertain in the Senate, where Democrats did not incorporate it into their health care legislation. Critics noted that mergers and some business practices were already subject to federal oversight and said that repealing McCarran-Ferguson provisions would do nothing to lower health care costs.

“The rhetoric surrounding repeal of McCarran-Ferguson does not match the reality of the situation,” said Karen Ignagni, president of America’s Health Insurance Plans, an industry group. “Health insurance is one of the most regulated industries in America at both the federal and the state levels.”

Mr. Obama signaled last October that he was interested in the issue when he said in a weekend radio and Internet address that Congress was right to study a possible repeal. At the time, he complained that insurers were gouging customers and executives were “earning these profits and bonuses while enjoying a privileged exemption from our antitrust laws.”

His statement on Tuesday represented the first time he had taken a formal position. Mr. Gibbs said the idea was not put into the overall health care plan posted on Monday because strategists believed there could be a bipartisan majority for repealing the exemption, separate from the main legislation.

The standalone repeal bill was devised as the first salvo in a dual-track strategy by Representative Nancy Pelosi, the California Democrat and House speaker, to advance elements of a health care overhaul one by one in case the comprehensive effort ultimately does not go forward.

Ms. Pelosi and Representative Louise M. Slaughter, Democrat of New York, pressed Mr. Obama for support during a private meeting last month, according to Congressional aides. “This industry has enjoyed a big giveaway for far too long,” Ms. Slaughter said in a statement after the president’s announcement Tuesday, “and it’s about time that it plays by the same rules as everyone else.”

The Democratic leadership allowed the latest version of the bill to be introduced on Monday by Representatives Tom Perriello of Virginia and Betsy Markey of Colorado, two freshman Democrats who voted on opposite sides on the larger health care legislation last year. Under the bill, health insurers would no longer be protected from liability for price-fixing, bid-rigging or dividing up market territories, according to the sponsors.

But after industry lobbying, the new version would not affect medical malpractice insurers.

About 95 percent of health insurance markets in the nation are “highly concentrated,” meaning that customers have only one or a few insurers to pick from. Proponents of repealing the antitrust exemption argue that such concentration has created an anticompetitive situation permitting huge premium increases.

But the Congressional Budget Office, a nonpartisan agency, reported in October that repealing the antitrust exemption for health insurers would not make a huge difference in premiums, in part because state laws generally already barred the activities prohibited by the federal bill. In terms of premiums, the report said, “the magnitude of the effects is likely to be quite small.”

Moreover, a Congressional Research Service report last month said that repealing the exemption could open the door to a flood of lawsuits challenging various insurer practices and could harm smaller insurers that share data because they do not have large pools of information of their own. If the result is that small insurers can no longer share information, the report said, “further consolidation in the insurance industry” would be “a likely, albeit ironic, possibility.”