A rebellious faction of House Republicans joined forces yesterday with Democrats on a bill that would guarantee new protections to all Americans in managed-care plans, increasing the odds that the House will pass stronger "patients' rights" legislation than the Senate has approved.

The compromise, reached on the eve of Congress's month-long recess, represents a setback for the House Republican leadership on an issue that is of acute concern to American voters. For weeks, emissaries of House Speaker J. Dennis Hastert (R-Ill.) have struggled without success to corral a growing cadre of party dissidents -- led by a core of lawmakers with medical backgrounds -- who favor broader reforms than the GOP supports.

In announcing the bipartisan agreement, Rep. Charles Whitlow Norwood Jr. (R-Ga.), a former dentist who has been a congressional leader in the drive to regulate HMOs, contended that Hastert will have no choice but to allow a vote on the bill he helped to craft, predicting that it will have nearly 100 Republican supporters by the time Congress returns after Labor Day. The GOP holds a five-vote margin in the House.

President Clinton, who has vowed to veto the Senate approach if it reaches his desk, was enthusiastic about the new approach. "Unlike the partisan Senate-passed bill, this bipartisan initiative is a Patients' Bill of Rights not just in name but in reality," Clinton said in a statement that urged Hastert to schedule a vote on "this long-overdue legislation" as soon as Congress returns to work.

But even before the bipartisan accord was announced, health industry and business lobbyists were already gearing up to derail it in a meeting with Rep. John A. Boehner (R-Ohio), who is helping to draft the narrower health care proposal favored by the GOP leadership. Boehner urged the lobbyists, whose groups recently launched high-priced advertising campaigns to try to thwart broader legislation, to step up their efforts over the August recess, according to participants. Several indicated that they will.

GOP leaders, meanwhile, immediately criticized the new bipartisan bill for adding potentially costly new regulations. House Education and the Workforce Committee Chairman William F. Goodling (R-Pa.), whose panel has jurisdiction over managed care along with two other committees, said he is "not going to be very happy" with any legislation that could raise health care costs and leave more Americans uninsured.

Although slightly less far-reaching than most Democrats prefer, the bipartisan bill introduced last night is substantially tougher in most respects than the approach favored by House GOP leaders and that contained in the Republican legislation adopted by the Senate last month.

Among the key differences, the new legislation would allow patients to sue health maintenance organizations for malpractice in state courts -- a change that is a pillar of the protections favored by Democrats and many consumer and medical groups but is anathema to the insurance industry and many businesses. Patients would be able to collect economic damages, although -- unlike under Democratic proposals -- they could win punitive damages only in certain instances.

The bipartisan bill would extend its protections to all 161 million Americans who have private health insurance. Most facets of the Senate legislation, in contrast, would apply to fewer than one-third of those people.

In addition to permitting lawsuits, the legislation unveiled yesterday would set up a relatively powerful means for patients to appeal to an outside panel when health plans deny care they believe they need. Those review panels would be made up of doctors and would be allowed to consider a wider range of factors in deciding what treatments are necessary. The Senate bill essentially would permit review panels to consider only whether an HMO had followed its own policies when it turned down a request for a specific medical service.

The House measure also would make it easier for patients to get bills paid when they go to hospital emergency rooms, to see medical specialists for chronic ailments and to take part in clinical trials of new therapies. Parents would be promised easy access to pediatricians for their children, and women would more readily be able to visit obstetrician-gynecologists and other women's health specialists.

Under the plan, HMOs may not forbid doctors who work for them to discuss expensive treatments with their patients, and may no longer give bonuses to physicians who stint on care.

"It puts medical decisions in the hands of doctors, not in the hands of Wall Street investors," said Rep. E. Clay Shaw Jr. (R-Fla.), a House leader on social issues and one of seven Republicans who stood with Norwood at a late afternoon news conference on the Capitol lawn.

House Minority Leader Richard A. Gephardt (D-Mo.) endorsed the legislation yesterday, saying that it contains meaningful reforms. "This consensus bill shows that the will of the people cannot be denied, that members from both sides of the aisle know this issue is too important to be put off for another year," Gephardt said.