SEARS HAS WON a decisive victory in its 13- year struggle with the Equal Employment Opportunity Commission. For six years in the mid-'70s, the commission investigated alleged employment discrimination by the nation's largest retailer, and in 1979, after much progress but no agreement on back pay, it sued the company in federal court in Chicago. The suit charged sex discrimination in hiring and promotions; it put heavy emphasis on statistics showing that women held primarily lower paying sales jobs while men were in more highly compensated commission sales.

The EEOC's own general counsel advised against the suit, warning that the government's case was riddled with "flaws and errors." Nevertheless, commission members voted to proceed as part of a broad plan to spur affirmative action by a number of the nation's largest companies.

Sears, the first major retailer to institute an affirmative action program, in 1968, set for itself long- range goals for the hiring and promotion of women and minorities, and pressured managers who did not meet these goals. Judge John Nordberg's opinion details the company's employment policies designed to benefit women and minorities -- some were adopted after the EEOC investigation began -- and states his opinion that "the sincere dedication and commitment of Sears management at all levels to affirmative action was evident from the testimony of the Sears' officials and employees, whom the court found to be highly credible witnesses."

What was the commission's case? Because any employment discrimination after 1964 was illegal, the commission sought back pay for early victims as well as accelerated affirmative action. The commission offered statistical evidence attempting to show that a low percentage of women in commission sales, for example, was evidence of discrimination. But the court, describing the statistical evidence as marred by coding errors, faulty basic assumptions and a number of other important flaws in analysis, rejected the argument. The evidence, the judge found, showed that Sears had made a substantial effort to recruit women into these positions, but the nature of commission jobs -- selling heavy farm equipment, automotive parts and aluminum siding on weekends, in the evening and at on- site locations -- made them less attractive to women. Similarly, while statistics showed that women were being placed in part-time jobs more frequently, Sears countered by showing that more women want part-time jobs.

This has been long and costly litigation, and it may not be over. The present EEOC chairman, Clarence Thomas, tried to settle the case, but the company sought complete vindication in court. It is estimated that Sears spent $20 million in legal fees defending the case and now, having won, may seek reimbursement from the government. Surely there was plenty of employment discrimination in this country back in the early '70s when this case was first opened, but the district court's opinion makes it clear that Sears has been a leader in taking effective affirmative action against it.