The federal government yesterday agreed to pay $2.2 million in back pay and retirement benefits to 130 women who brought a class action lawsuit claiming widespread sex discrimination against women in professional jobs at the Department of Energy and its predecessor agencies from 1975 to 1977.

U.S. District Judge Thomas A. Flannery gave preliminary approval yesterday to the settlement agreement, which includes a complex formula for awarding the money based on discrimination experienced by each individual in entry-level salary and promotions.

Lawyers for the women estimated that the payments to the individual women would average about $17,700.

The Justice Department and the Department of Energy last night mailed notices to each of the women, asking them for their comments on the proposed formula and advising them of a hearing scheduled for May 6. At that proceeding, known as a "fairness hearing," they can register any objections to the settlement agreement.

In 1978, the Justice Department acknowledged a pattern of sex bias in hiring and promotion at the old Energy Resources and Development Administration and its predecessor, the Atomic Energy Commission, both of which were exempt from civil service requirements for filling government jobs. The Department of Energy, created in 1977 to take over ERDA, was subject to the civil service hiring and promotion requirements.

The professional women who will share the $2.2 million in damages include, among others, scientists, lawyers, procurement officers and personnel staff. Lawyers familiar with with the case said yesterday that 52 of the 130 women who share the award are now working at DOE.

The government decided to admit liability in the case in 1978 after its own statistical experts showed an even wider disparity between men and women in salary and job grade levels than had been claimed by the women who filed the lawsuit.

The case was first brought to the federal court by June Chewning, a manpower analyst and a recognized expert in analyzing work patterns at nuclear plants, who contended she had poor promotion and transfer opportunities and was forced to do clerical work that could have been done by men in the office at lower ranking jobs. Initially, some 330 employes were included in the class of women who were included in the lawsuit, but over years of litigation, that number has been brought down to 130.

The amount of money awarded to the women under the formula will include payment for discrimination in salary at the time an employe was hired and back pay for promotions an individual would have achieved if she had followed the expected career path in the civil service.