The Supreme Court let stand yesterday a U.S. Court of Appeals ruling here that said syndicated columnists Rowland Evans and Robert Novak could not be sued for allegedly libeling a Marxist professor seeking a job at the University of Maryland.

The sharply divided appeals court said last December that the columnists could not be sued for disparaging statements written about professor Bertell Ollman because those statements were "entitled to absolute First Amendment protection as expressions of opinion."

The 6-to-5 vote split the appeals court's political lineup, with a conservative majority favoring the columnists and with conservative Reagan appointee Antonin Scalia joining liberals in arguing that Ollman was libeled.

Two members of the high court's conservative wing yesterday failed to muster the two other votes necessary to agree to hear Ollman's appeal and perhaps overturn the conservative lower-court judges' views.

Justice William H. Rehnquist, joined by Chief Justice Warren E. Burger, argued yesterday that the "result reached by the Court of Appeals in this case is nothing less than extraordinary."

The case involved legal standards that should apply in treating statements of opinion and statements of fact.

Various courts have said expressions of opinion are generally protected from libel suits, while statements of fact do not enjoy that privilege. The high court, however, has not defined what is "fact" and what is "opinion."

Ollman, a New York University professor who had been nominated to head the University of Maryland political science department, sued Evans and Novak, claiming that he was denied the job because of the column.

The appeals court majority said the First Amendment protects the columnists from Ollman's $6 million suit.

A point that split the appeals court was how to treat the columnists' statement that Ollman had "no status within the profession, but is a pure and simple activist."

Rehnquist said the appeals court majority relied on a portion of a 1974 Supreme Court decision, Gertz v. Welch, regarding libel protections for statements of opinion.

"Lower courts have seized upon the word 'opinion' in that decision," Rehnquist said, to "solve with a meat axe a very subtle and difficult question" of libel law protections.

Rehnquist urged the court to hear the case, saying he found it "impossible to disagree" with liberal appeals Judge Patricia M. Wald's characterization of the key statement as an "assertion of fact for which its author can be made to answer . . . in suit for libel."