Sen. Mark O. Hatfield (R-Ore.), though he has taken Israel's side against the administration's proposed $8.5 billion radar-aircraft sale to Saudi Arabia, said yesterday that anti-Semitism is rising in the United States as a partial result of what he called the "apparent intransigence" of Israeli Prime Minister Menachem Begin.

Hatfield raised the point in a breakfast meeting with reporters, and several other senators later said they, too, were hearing increasing talk, prompted in part by the controversy over selling surveillance planes to the Saudis, that they interpret as anti-Semitic as well as unfavorable to Begin.

Sen. Joseph R. Biden Jr. (D-Del.) said he was approached on the train from Delaware to Washington yesterday morning by a businessman who told him, "I realize the only reason you oppose the sale is because of your Jewish constituents, but I want you to be objective."

"I have never experienced anything like this in my life in terms of basic prejudice," said Sen. David Durenberger (R-Minn.), speaking of reaction to the arms sales debate.

Sen. Daniel Patrick Moynihan (D-N.Y.) said he has been told by a dozen or more senators that supporters of the sale have argued that its defeat would ultimately hurt American Jews as well as Israel.

"I think there is a latent anti-Semitism in this country," Hatfield told reporters, adding that he has found a "definite increase" in anti-Semitic expressions in both mail from constituents and conversations during visits home to Oregon.

Hatfield pointed to economic frustrations and concern over the availability of Arab oil as contributing factors, adding that Begin is "only a trigger" that sets off "this kind of thinking." Hatfield specifically cited the Israeli bombing of an Iraqi nuclear reactor, along with Begin's justifications for it, as a "great arrogance" that prompted a negative response in the United States.

Even Oregon, despite its progressive reputation, had a flare-up of Ku Klux Klan activity in the 1920s, Hatfield noted, although the state later went on to elect a Jewish governor. "It's there all the time," he added, referring to latent anti-Semitism.

More recently, the desecration of a Portland synagogue prompted formation of a citizens' organization aimed at combating bigotry of all kinds, which Hatfield cited as one example of ways to contend with the problem. He also said he was making a point to answer "nut" mail that he previously threw away unanswered, lest people interpret his silence as agreement.

As for his opposition to sale of the Airborne Warning and Control Systems (AWACS) to the Saudis, which Begin has lobbied against, Hatfield said he feels as though he is "facing down a double-barreled shotgun."

But he said he remains opposed to the sale because he sees "a greater degree of danger" from "escalation in an area that could produce a confrontation with the Soviet Union." It is only "conjecture" that defeat of the AWACS sale--which comes up for a vote today in the Senate--could heighten anti-Semitism in this country.