The American Association of University Professors has formally censured the University of Maryland, charging it violated long-established standards of academic freedom by refusing to hire Marxist professor Bertell Ollman last year.

Delegates of the 70,000-member AAUP, the nation's largest professional organization of college teachers, voted 143 to 101 on Friday at its annual convention in Houston to add Maryland to its censure list.

Forty-six institutions are now on the list, which serves as a "red flag to the academic community," according to an AAUP spokesman, but does not carry any tangible sanctions.

University of Maryland President John S. Toll called the censure an "improper outside interference in university affairs," and charged in a statement that by its vote, the AAUP "diminishes its credibility," and "has itself become a threat to academic freedom."

Reached by phone yesterday, Tollsaid, "I know of other univerities that have been censured that have not felt any effect. But it is not something that is welcomed."

Ollman has been selected from more than 100 applicants by a university search committee to head the department of government and politics at the university's College Park campus.

But Toll, then newly installed, rejected that nomination last July, a few months after several members of the university's Board of Regents, some state legislators, and then-acting Gov. Blair Lee III questioned the wisdom of appointing a Marxist to a top academic post at a state university.

That rejection, the AAUP contended, could be because Ollman "failed to pass an ideological test or because the institution was unprepared to resist political pressure," according to a report issued by an AAUP committee.

The report also said that Toll refused to discuss the case with the search committee, and would not allow his administrators to talk. Academic freedom at the university is "under a cloud," the report continued, with procedures for making appointments providing "inadequate safeguards against arbitrary and improper decisions."

Nevertheless, the committee recommended against censure because of insufficient evidence of "an actual violation." For the first time in 15 years, a spokesman said, the delegates reversed the recommendation of the committee.

Reached at home yesterday, Ollman, who is suing the Unversity for $300,000 in damages and seeking a court order appointing him to the post, said he was "delighted but not surprised" by the AAUP vote.

"The AAUP is a nonpolitical, nonradical, highly professional organization noted for its fairness," said Ollman, a 41-year-old associate professor at New York University. "A lot of academic fence-sitters are going to see that what I've been saying is true. I hope even the judge will be influenced."

Barbara Bergmann, a professor of economics at the University of Maryland and the president of its AAUP branch, said she voted for the censure.

Although a censure often has the effect of chasing away qualified faculty, Bergmann said that "I'm hoping in this case the censure will have a good effect, in persuading President Toll to make a break from the traditions of ignoring faculty opinion whenever there's pressure to do so."