Former U.N. secretary general Kurt Waldheim won a convincing victory in the runoff of Austria's presidential election today following an acrimonious campaign dominated by allegations that he covered up his Nazi past.

Austrian commentators interpreted the result as both a personal success for Waldheim and a protest against the unpopular Socialist government. But they also raised questions about whether the new president would be able to function effectively abroad in the likely event of continuing press revelations about his past.

Waldheim's victory marked the first time since World War II that a nominee of the conservative People's Party has captured the Austrian presidency, a prestigious but largely ceremonial post. Elections for the Socialist-controlled parliament are due early next year.

The final election returns gave Waldheim 53.9 percent of the vote, with 2.46 million, against 46.1 percent, or 2.11 million, for the Socialist candidate, Kurt Steyrer. In the first round on May 4, Waldheim received 49.6 percent of the vote, with 43.7 percent going to Steyrer and the rest to fringe candidates.

Speaking on television after the results were declared, the former U.N. chief said he would try to use his "moral authority" to promote a climate of tolerance in Austrian politics. He said he was gratified by the margin of his victory, which was greater than expected.

"This result is a demonstration of the confidence the Austrian people have in me," said Waldheim, 67, a former foreign minister and unsuccessful presidential candidate in 1971.

[American Jewish organizations reacted with anger to Waldheim's election, and Israel, expressing "deep regret and disappointment," hinted that the level of diplomatic relations between the two countries would be reconsidered.]

The controversy over Waldheim's war record erupted in March when the World Jewish Congress released documents showing that he had hidden key details about his service as a German intelligence officer in the Balkans between 1942 and 1945. Evidence has since emerged suggesting that he was in a position to be aware of German atrocities, including the deportation of Jews and mass reprisals against civilians, even if he was not himself guilty of war crimes.

Conceding defeat, Steyrer, a physician and former minister of health, said that the stream of allegations had not helped his campaign and may even have harmed him. A similar view was expressed by the secretary general of the People's Party, Michael Graff, who said that "Waldheim's generation" had rallied around him.

"People who were obliged to serve in the German Army were not going to allow themselves to be described as war criminals," he said.

Campaigning on the slogan "Austrians will decide for themselves," Waldheim exploited a widespread feeling here that Austria itself was being put on trial by the rest of the world. Austrians have traditionally sought to depict themselves as "Hitler's first victims," despite the fact that the 1938 annexation by the German Third Reich was supported by many Austrians at the time.

Aware that there was little electoral benefit to be gained from criticizing Waldheim's war record, Steyrer stuck to traditional themes during the campaign, such as the need to defend the welfare state. It was only during the last few days that he began to stress that Austria needed the respect and trust of the world.

As a longtime Socialist Party figure, Steyrer drew criticism because of corruption scandals involving the present Socialist government.

Steyrer served in World War II as a German Air Force medic and after the war he was imprisoned briefly on charges that he carried out illegal abortions, a damaging accusation in this overwhelmingly Catholic country. He has strongly denied such allegations, although he has said that he left the Roman Catholic Church because he disagreed with its opposition to abortion.

The predominantly conservative Austrian press and television largely steered clear of the controversy that has raged in other western countries. With the exception of Profil, a left-wing Austrian weekly, practically all the revelations about Waldheim's war record were reported by foreign news organizations.

While acknowledging that he could have been more candid about his past, Waldheim has consistently denied any wrongdoing. He contended that he and his family were opposed to the Nazis politically but that, as a German officer, he was subject to strict military discipline.

Outgoing President Rudolf Kirchschlaeger told Austrians in a television address April 22 that there was not enough evidence for a criminal charge against Waldheim. Yugoslavia, which accused him of war crimes in a 1947 report to a U.N. war crimes commission, has refused to make its findings public.

Two months ago, a U.S. Justice Department official recommended that Waldheim be put on a list of persons barred from entering the United States because of Nazi activities. Asked today about that move, Waldheim replied that he was seeking legal advice and hoped a solution would be found.

Justice Department officials said this weekend that as head of state, Waldheim would be immune from being barred entry. A source associated with Waldheim said the former U.N. official would continue legal efforts for full personal vindication in the United States.

Waldheim today publicly shrugged off foreign criticism of his election as "unimportant" and said he wanted to devote his attention to Austria's domestic problems.

The president-elect received a rapturous reception tonight from hundreds of people celebrating his victory at the headquarters of the People's Party.

"I think Waldheim was right not to talk about what he did in the war," said Susanne Weichesmiller, who said her family had scoured the streets for crusts of bread then. "We Austrians are fed up with the war. It's better to forget it."

Michael Rascher, a younger Waldheim backer, said: "We have had 41 years of peace and don't want to think back to those times. It's good that we know there was a war, and the reasons for the war, but it's better not to know about the actions of individuals who were forced to fight in the war whether they wanted to or not."

In official biographies, Waldheim omitted reference to his service on the staff of Gen. Alexander Loehr, who was executed for war crimes.