SAN FRANCISCO -- A federal appeals court ruled for the first time Tuesday that the government cannot revoke doctors' prescription licenses for recommending marijuana to sick patients.

A three-judge panel of the 9th U.S. Circuit Court of Appeals unanimously found that the Justice Department's policy interferes with the free-speech rights of doctors and patients.

"An integral component of the practice of medicine is the communication between doctor and a patient. Physicians must be able to speak frankly and openly to patients," Chief Circuit Judge Mary Schroeder said.

The 9th Circuit upheld a 2-year-old court order prohibiting the government from stripping doctors of their licenses to dispense medication. The policy was blocked before any licenses were actually revoked.

The dispute is one of several cases resulting from medical marijuana laws on the books in eight states.

The government argued that doctors were aiding and abetting criminal activity for recommending marijuana because it is an illegal drug under federal narcotics laws.

But the appeals court said doctors have a constitutional right to speak candidly with their patients about marijuana without fear of government sanctions.

The court said doctors could get in trouble only if they actually helped patients obtain marijuana. Merely recommending the drug "does not translate into aiding and abetting, or conspiracy," Schroeder said.

The Justice Department had no immediate comment.

Graham Boyd, an American Civil Liberties Union attorney, had urged the judges to preserve the sanctity of doctor-patient interactions. "That is speech that is protected by the First Amendment," he argued.

Measure passed in 1996

The case was an outgrowth of a measure approved by California voters in 1996. It allows patients to use marijuana with a doctor's recommendation.

Following the measure's passage, the Clinton administration said doctors who recommend marijuana would lose their federal licenses to prescribe medicine, could be excluded from Medicare and Medicaid programs, and could face criminal charges. The Bush administration continued the fight.

Other states with medical marijuana laws are Alaska, Arizona, Hawaii, Maine, Nevada, Oregon and Washington.