Uniroyal Inc. has agreed to a $5.2 million settlement of a sex discrimination case that caused the federal government to bar the huge rubber company from receiving federal contracts last June, it was announced yesterday.

In announcing the back pay award to 750 women employes from Uniroyal's Mishawaka, Ind., plant, Labor Secretary Ray Marshall said the company will not be eligible again for federal contracts.

When Uniroyal was cut off from new federal business four months ago, it had more than $36 million in contracts and was the largest firm to have been found in violation of executive orders banning race and sex discrimination by federal contractors.

Labor Department officials said the $5.2 million back-pay award, to be paid in two installments through next June, is the largest such award since the landmark American Telephone & Telegraph settlement in 1973. AT&T paid $52 million in both onetime and continuing payments through this year, officials said.

In addition to the back-pay award, the Uniroyal settlement restored pension benefits and seniority status to the women workers. Those who retired will receive pension benefits as though they had never been laid off.

Because a separate private suit was filed by the women under the Civil Rights Act of 1964, final disposition of the Uniroyal case is subject to approval of the federal courts.

The debarment order had been based on Labor Department allegations that Uniroyal refused to cooperate and gave false responses during a probe of the women's complaints of sex bias in hiring and layoff practices at the Mishawaka plant.

The company, the nation's third largest tire manufacturer, unsuccessfully challenged the department's action in U.S. District Court. The case was on appeal when the settlement was worked out.