NEW YORK (AP) _ A federal court judge has thrown out a lawsuit by 20 anesthesiologists who challenged a health maintenance organization's authority to dictate standards of patient care.

Judge Denise Cote in U.S. District Court in New York ruled Tuesday that the antitrust law which the doctors used against Aetna Health Plans Inc. didn't apply.

``The fact that HMOs have their critics does not obligate the courts to create ... a novel application of antitrust laws,'' Cote said.

The ruling is a blow to doctors who increasingly are asking courts around the country to give them back the powers over individual medical care decisions that HMOs have taken away in the name of efficiency.

The attorney for the doctors called the decision erroneous and said it will be appealed.

HMOs restrain costs by imposing medical guidelines on doctors and closely scrutinizing treatment decisions _ a situation that has reduced doctor influence and income.

The plaintiffs in the 1995 suit included 20 anesthesiologists at hospitals on suburban Long Island who had negotiated contracts with Aetna Health Plans of New York.

``We attempted to negotiate modifications in the contract so the doctors could fight for their patients' rights,'' Whitney Seymour, the doctors' attorney said Wednesday.

For instance, the doctors demanded that Aetna appoint an independent committee to resolve their medical disputes with the company.

They also complained that Aetna wanted the right to change the terms of its contracts with the doctors without their consent.

The doctors claimed that when they made their demands to Aetna, the company threatened to stop sending patients to their hospitals, putting their jobs in jeopardy.

Aetna's position violated federal antitrust law because it restrained the doctors' ability to compete, the suit contended.

Aetna said Wednesday that Judge Cote's decision established that it has the right under antitrust law ``to set standards for providers in its efforts to deliver high quality, cost effective health care coverage.''

This right is critical for managed health care to work and does nothing to undermine the quality of patient care, the company said.

The doctors refused to agree to elements of Aetna's standard contract, which had been approved by the state department of health, Aetna said.

The decision ``enables us to bring the best value and quality in health care to our members and derails this attempt by certain providers and their lawyers to undermine managed health care, said Clifford Klima, head of Aetna's New York metropolitan health plan.

Seymour has represented a number of New York City area doctors who have sued HMOs in recent months. Most of the suits are pending.