Anne Arundel Community College reached an out-of-court settlement today on a sex discrimination suit filed in 1978, by tentatively agreeing to pay 89 women teachers a total of $550,000 in back pay over the next four years.

The settlement, worked out late this afternoon by lawyers for the college, Anne Arundel County and the teachers, also reportedly includes increases in current pay and improvements in promotion guidelines.

Details were withheld pending notification of all the women involved in the class action suit, some of whom have moved outside the state since it was filed, said assistant county solicitor Karen Murphy Jensen.

The settlement is subject to a routine federal court hearing in Baltimore Dec. 15 and comment from the complainants, Jensen said. It is expected to end the five-year controversy that has split the 9,000-student college in Arnold, Md. U.S. District Court Judge Frank A. Kaufman will make a final ruling after the hearing.

The suit alleged that the college administration and board of trustees discriminated against women in all departments in pay, benefits and promotions. About half of the school's 175 full-time faculty members are women.

The college's board of trustees has continually denied the allegations, but said it wanted to settle the case out of court to avoid a long and expensive court hearing. Legal fees for the college so far have totaled over $78,000, according to the college's finance office.

Neither college officials nor the teachers' spokesmen were available for comment on the settlement.

The settlement did not resolve whether the college's insurance company, Continental Casualty Co. of Chicago, will reimburse the college and the county for the cost of the settlement under the school's $2 million indemnity policy. The insurance company has appealed a ruling by the Maryland State Insurance Division ordering it to pay the cost.

The company claims the college violated the terms of its contract by discriminatory behavior. Its refusal to pay the claim at one time threatened any chance of settlement.

Today's agreement came about after a flurry of conference calls between lawyers for both sides and Judge Kaufman. After years of languishing, negotiations on a settlement intensified last month when Kaufman set a deadline for reaching a settlement or going to court. He then extended the original two weeks to a month, which ended today.

The suit was originally filed by two teachers no longer with the school, Anita McCain, an English teacher, and Elizabeth Sinnigen, a math teacher. McCain now lives in Oklahoma and Sinnigen is in veterinary school in Philadelphia. In 1981, English teacher Jean Turner-Schrier joined as class representative.

Of the 89 included in the suit, 50 have alleged equal-pay violations, but all will receive part of the back pay settlement, said Jensen.