Gulf Oil Corp. was charged by the Justice Department yesterday with taking part in an international cartel to fix the price of uranium.

The Criminal information, filed in U.S. District Court in Pittsburgh, accuses the firm of violating the Sherman Antitrust Act by conspiring with other uranium producers between 1972 and 1974 to sell uranium only at discriminatorily high prices to purchasers and not at all to Westinghouse Electric Corp.

The charge is a misdemeanor, punishable by a $50,000 fine, rather than a felony with a possible $1 million fine, because the government didn't have sufficient evidence that the conspiracy continued past Dec. 21, 1974, a Justice Department spokesman said yesterday.

It was only after that date that the law allowed felony prosecutions under the criminal sections of the Sherman Act, he said. Because the charge was a misdemeanor, it did not require a vote by the federal grand jury in Washington which has been investigating the uranium cartel for the past 18 months, the spokesman added.

The charge against Gulf mentions the firm's Canadian subsidiary, but does not name the other "co-conspirators" in the cartel. Nor does it charge specifically that the conspiracy affected consumer prices of energy in the United States, an issue now being contested in civil suits.

The price of "yellowcake," the raw uranium used to make fuel for nuclear power plants, climbed from $6 a pound to $41 a pound in the early 1970s. Westinghouse is suing Gulf and other members of the cartel over the issue and Gulf filed a multi-million-dollar countersuit yesterday.

A gulf spokesman in Pittsburgh said yesterday that the corporation felt the charge was "completely unfounded."

Gulf believes the government was "unjustified" in singling it out for prosecution when its Canadian subsidiary didn't act alone, the spokesman added.

The company's participation in what it termed the "foreign uranium marketing arrangement" was at the "express direction of the government of Canada," the spokesman said.

And the Canadian marketing arrangement was similar to quotas and reference prices initiated by the U.S. government to protect such domestic industries as steel, television and shoes, he said.

The Canadian government is known to have been concerned about the antitrust investigation. Attorney General Griffin B. Bell said yesterday that his Canadian counterpart had asked him about the case during a recent visit.

But Bell said there had been no political pressure from the State Department or White House to tailor the decision in the uranium cartel case to satisfy the Canadians.

The misdemeanor charge against Gulf is the only criminal prosecution that will be produced by the uranium cartel investigation, the Justice Department spokesman said. But he noted that civil action against Gulf or other participants in the alleged conspiracy is still a possibility.

Joint hearings on Capitol Hill last year by investigators for the House and the state of New York established that American subsidiaries of some foreign corporations were also involved in the uranium cartel.

Documents introduced at those hearings indicated that Gulf and the other firms were enthusiastic rather than unwilling partners in what Gulf's spokeman termed yesterday the Canadian-government-sponsored arrangement.

William Haddad, who headed the New York Investigation, said yesterday that Gulf "continues to profit from the conspiracy, and their executives have splipped through the white collar loophole. Stealing a 30-cent loaf of bread is more of a crime in this country than designing and operating a billion-dollar cartel."