A Maryland official has ordered a major insurance company to stop setting different disability and life insurance rates for men and women, a decision that could affect other insurance carriers that do business in the state.

The order, issued by a hearing examiner for the state Human Relations Commission after an 11-year proceeding, also requires the company, Equitable Life Assurance Society, to include pregnancies in disability coverage and eliminate income requirements for people who want to buy disability insurance.

Hearing Examiner Merry C. Hudson found that Equitable had discriminated against women by using sex-segregated actuarial tables in setting insurance rates. She found that the company's refusal to sell disability insurance to certain blue-collar and clerical workers because of their incomes had an adverse impact on women and blacks.

The case was brought against Equitable by the Human Relations Commission in 1975.

Risselle Fleisher, general counsel for the Human Relations Commission, said the ruling could be "monumentally important" in its effect on the insurance industry.

However, a bill passed this year by the legislature could invalidate the decision unless the bill is vetoed by Gov. Harry Hughes. The bill would transfer authority over insurance sex discrimination cases from the Human Relations Commission to the state insurance commissioner.

A spokesman for Hughes said he had not decided whether to veto the bill.

"If the governor doesn't veto that bill, this case could go into a strange kind of limbo and I don't know what will become of it," said Fleisher. "We may be in the bizarre position of never being able to enforce this decision."

Barrett Freidlander, an attorney for Equitable, refused to comment on the case yesterday, saying he had not yet seen the opinion.

Fleisher said she expected Equitable to appeal the decision, first to an administrative panel and, if necessary, in the courts.

Insurance companies commonly have set different insurance rates for men and women.

Fleisher said Equitable had argued that its disability rates for women were higher because women file more claims than men.

Some clerical and other low-paid workers are unable to obtain disability insurance because carriers conclude they would be more likely to file claims with the intent of getting more money in benefits than they do in wages, according to Fleisher.

Companies consider some blue-collar occupations hazardous and refuse to provide coverage for that reason, she said.

The decision was hailed by the National Organization for Women, which has been pressing for changes in insurance laws across the country.

"The commission's ground-breaking decision against the Equitable corporation recognizes that insurance discrimination causes major economic harm to women and minorities," said Twiss Butler of NOW's insurance project in Washington.