Uniroyal Inc., the nation's third largest rubber manufacturer, was barred yesterday by the Labor Department from doing any more business with the government until it complies with federal anti-discrimination orders.

Uniroyal, which has annual sales totalling $2.7 billion and at least $36 million in federal contracts, is the largest firm so far to be found in violation of executive orders banning race and sex discrimination by government contractors.

It was the company's second blow in as many days from the government.

On Thursday, the Council on Wage and Price Stability cited Uniroyal, along With B.F. Goodrich and Firestone rubber companies, for "probable noncompliance" with the administration's wage guidelines. The penalty for guideline violations is also contract debarment, which is now a moot point in the case of Uniroyal.

The anti-discrimination debarment order, signed by Labor Secretary Ray Marshall, accused Uniroyal of refusing to cooperate in a probe of job bias charges and of giving "false answers" to questions posed during the investigation.

Marshall found that Uniroyal, contrary to its sworn testimony, classified employes by sex for hiring, placement and other purposes and maintained separate male and female folders and seniority lists at least through 1970.

Most of the government's complaints involved refusal to cooperate in the investigation, which is, in itself, grounds for debarment, according to the government. "We never got to the merits, because they wouldn't let us look at the evidence," said a Labor Department official. "We debarred them because they wouldn't cooperate."

While the Labor Department debarment referred to racial as well as sex discrimination, the case arose primarily from sex bias complaints dating back to the closure of Uniroyal's footgear operations at a plant in Mishawaka, Ind., in 1968. Thomas R. Ewald, attorney for the women, said they were laid off although the company was retaining and hiring men with less experience.

As recently as last Monday, the women filed suit to prod Marshall to act on a department debarment recommendation that had been pending for 14 months. There had been speculation - denied by Marshall - that he held up action to keep up pressure on the company to comply with the wage guidelines during recent contract negotiations.

Uniroyal declined comment but late yesterday submitted a one-sentence request for a stay from Marshall. Department officials said a decision on the stay request will be made quickly, with the debarment order remaining in effect until the decision is made.

The order provides that "Uniroyal's present government contracts and subcontracts are canceled, terminated or suspended and that Uniroyal be declared ineligible for further contracts and subcontracts" until it can "satisfy" the government that it is complying with equal opportunity rules.

In practice, however, each contracting agency will decide whether it is feasible to cancel existing contracts, said department spokesman Bob Cuccia. Often, he said existing contracts are filled but not renewed.

Ewald said he understands that, in addition to Uniroyal's $36 million in direct contracts, the company has "millions" in subcontracts.

He said the women do now want to deny business to Uniroyal, which is regarded by financial experts as financially shaky, but feel entitled to relief, including roughly $18 million in back pay, reinstatement, pension restitution and anti-discrimination job protections for the future.

Prodded by suits filed by the 500 Mishawaka women workers, the Labor Department conducted investigations in 1972 and 1976, resulting in a formal complaint by the department in 1976. The complaint alleged that the company discriminated against female and minority group employes and failed to take affirmative action to remedy the practices.

In the course of hearings on the complaint, "the company refused to provide necessary information about its employment practices, even after being ordered to do so by the administrative law judge," and "falsely responded to inquiries from the department," the department said.

Cuccia said the Uniroyal cutoff is the 21st contract debarment since President Johnson signed an executive order invoking such sanctions against government contracts in 1965. CAPTION: Picture, RAY MARSHALL . . . signed debarment order