A coalition of 25 health maintenance organizations said Monday that it was willing to accept substantial federal regulation - much more than the Republican leaders of Congress want.

In a move that they said should restore public confidence in their industry as it is buffeted by sharp partisan attacks, the HMOs endorsed a series of guarantees, including coverage of emergency room care, grievance and appeal procedures for patients and assured access to medical specialists.But the group said it was opposed to one major provision demanded by Democratic leaders: a wide expansion of patients' ability to sue HMOs and insurance companies when medical benefits are improperly denied.

The coalition, known as the HMO Group, said that patients could resolve such disputes by appealing to an independent panel of medical experts, and that lawsuits would unnecessarily increase costs and reward lawyers.

The HMOs, which are mostly nonprofit organizations, supported legislation being developed by Sens. John Chafee, R-R.I., and Bob Graham, D-Fla.

The Chafee-Graham plan is intended as a compromise between a Democratic leadership proposal, which includes the right to sue, and legislation being drafted by Republican leaders of the Senate and the House, who promise to protect patients without entrusting vast new power to the federal government.

George Strumpf, senior vice president of HMO Group, which represents 25 HMOs with more than 6 million members in 26 states, praised the Chafee-Graham legislation.

"It's a moderate proposal," Strumpf said. "It represents the best interests of consumers, providers and health plans. It strikes a balance. That's what's lacking in the bills introduced by other people."

The HMO Group includes some of the nation's oldest and largest HMOs: Kaiser Permanente, based in Oakland, Calif.; Group Health Cooperative of Puget Sound, in Seattle; HIP Health Plans, in New York City; Harvard Pilgrim Health Care, based in Brookline, Mass.; Health Partners, of Minneapolis; and the Fallon Community Health Plan, in Worcester, Mass. The HMO Group has offices in New Brunswick, N.J., and Washington.

Bruce Lesley, a lobbyist at the National Association of Children's Hospitals, said Monday night, "The Chafee-Graham legislation could be the basis for a bipartisan agreement. It includes the most important protections for patients, including children, while leaving out the most controversial proposals found in other bills."

The umbrella group that lobbies for managed-care companies, the American Association of Health Plans, is running television advertisements that oppose legislation to regulate the industry. "When politicians play doctor, real people can get hurt," the commercials say.

Mark Merritt, a vice president of the association, said it had spent $2 million on advertising and public relations this year, and would spend much more. "The budget keeps growing every day," he said.

For-profit companies like the Cigna Corp., which have branched out from traditional health insurance into managed care, also are resisting federal legislation. The Health Benefits Coalition, which includes employers and insurance companies opposed to "patient protection" bills, said it had spent $1.5 million on radio and print advertising, direct mail and public relations since January.

But the HMO Group has adopted a detailed statement of principles that is generally consistent with the Chafee-Graham bill.

"We are bewildered to see what the public thinks about our organizations and the industry now," said Daniel Wolfson, president of the HMO Group. "Patients feel they are not in control of their health care. They feel powerless. Legislation could defuse that distrust."