A Supreme Court ruling yesterday limiting the right of patients to sue managed-care companies for malpractice was a major victory for the firms, but industry spokespeople said it will benefit patients, too.

"In the industry, you may see the premiums go down or not go up as much," said Alan Lipshitz, legal director for Blue Cross Blue Shield Association.

But while health maintenance organizations were celebrating, it was clear that the debate over patients' rights and limits on health care providers' liability won't go away but will shift to another forum: the fight over a federal patients' bill of rights.

"It means that the patients who are improperly denied health care will have no ability any longer to hold their health plans accountable and liable for the harm that they caused even when it results in death," said Ron Pollack, executive director of Families USA, a health care consumers organization. "The only thing that would protect patients is if Congress adopted and the president signed a patients' bill of rights," Pollack said.

The 9-to-0 decision affirmed a 1974 federal statute, the Employee Retirement Income Security Act (ERISA), prohibiting states from allowing patients to sue HMOs for refusing to pay for treatment. About 72 million people are covered by HMOs.

"Our concern since the outset has been that an unfavorable ruling could result in more litigation and greater costs with resolving such litigation," said David Carter, an Aetna Inc. spokesman.

The justices voted to strike down two Texas lawsuits that would have made Aetna and Cigna Corp. liable for refusing to pay for a painkiller and for not allowing a hysterectomy patient a longer stay in the hospital, respectively.

Officials of HMOs say the court has established some limits to liability in health plans that will cut down on "frivolous" lawsuits. It allows employers and insurers to control costs and may lessen the burden for everyone, Lipshitz said.

The Association of Trial Lawyers of America, which filed a brief supporting the injured patients, was not pleased with the ruling. "Basically, this decision insulates HMOs from any responsibility for delaying or denying care that injures patients and shifts responsibility unfairly to doctors and others, who are forced to, who are told what medical care they can give by the HMOs," said Carlton Carl, the group's spokesman.

Managed-care companies will have little incentive to approve expensive but medically necessary treatments, John C. Nelson, president of the American Medical Association, said in a written statement.

Benjamin Zipursky, a professor at Fordham Law School in New York who specializes in tort law, said the court's decision will spur Congress to reexamine the contentious idea of a patients' bill of rights.

"What this decision states is that the federal ERISA law preempts all state private rights to sue HMOs for the injury one suffers as a result of the HMOs' decision that something doesn't need to be covered," Zipursky said.

The debate will shift now to whether there should be a federal right to sue for redress after one is injured. Justice Ruth Bader Ginsburg said that either the courts or Congress need to create a federal avenue for a patient to be compensated for HMO negligence.

Representatives of HMOs said there are already several ways for people to seek the medical care they need or other redress before filing a lawsuit, and that in the cases before the court, a number of steps were ignored or skipped.

"What the court has done has relegated discussion back to existing remedies," said Karen Ignagni, president and chief executive of America's Health Insurance Plans, a trade group for health insurers. Some of those means include filing grievances within and outside the company and seeking federal injunctive relief.

Patients' advocates said those mechanism do not work. In many cases, there is not sufficient time to contest an HMO's decision if a patient needs an extra stay in the hospital or a specific medication, they said.

Across the board, stocks for the top U.S. health insurers dipped yesterday. Aetna, the No. 3 U.S. health insurer, dropped $1.69, to $83.93. Cigna closed at $67.25, down $1.90. The No. 1 insurer, UnitedHealth Group Inc., fell $1.77, to $62.23, and No. 2 WellPoint Health Networks Inc. slid $2.68, to $110.38.