A new court ruling, implying that Maryland's largest medical malpractice insurance company must offer coverage to licensed physicians regardless of the risks of their specialties, could force skyrocketing premiums even higher, the company's president contends.

The Medical Mutual Liability Insurance Society of America, which covers about 75 percent of the state's privately insured doctors, was ordered Friday by Baltimore Circuit Judge Thomas Ward to restore malpractice coverage to a Baltimore obstetrician-gynecologist.

The company's president, J. John Spinella, said it should be allowed to refuse coverage to certain physicians it considers lawsuit-prone.

"Not every doctor that's got a license is a good risk," Spinella said. "If we had to write insurance for everybody, we probably wouldn't be able to get reinsurance, and then we couldn't even insure the good doctors."

Ward ruled in a case brought by Dr. Michael Magan, whom the company considered too high a risk because of three past malpractice claims. It had refused to offer him coverage for obstetrics, generally considered the highest-risk medical specialty.

Ward ruled that Insurance Commissioner Edward J. Muhl must order Medical Mutual to provide Magan with an obstetrics policy at its standard rate and permanently barred the company from refusing him coverage.

The judge also ruled that the intent of the state General Assembly in creating Medical Mutual in 1977 was "to provide Medical Mutual as a vehicle for insurance for all physicians registered and properly practicing in the state of Maryland."

While Ward's ruling immediately affects only Magan's case, the impact on the state could be far-reaching if Medical Mutual appeals and the decision is upheld.