VIENNA, JAN. 28 -- An international panel of six military historians, appointed by Austria, spent four hours today questioning President Kurt Waldheim in an effort to assess charges of his involvement in war crimes.

The panel had submitted its questions in advance. Afterward, panel chairman Hans Kurz of Switzerland said the session was "hard but useful. President Waldheim answered all the questions we put to him. Some were personal and very delicate.

"Of course, he did have some lapses of memory about his wartime career in the Balkans, but that is normal," Kurz said. He dismissed complaints that the prior submittal of questions worked to Waldheim's advantage, saying the panelists "are no fools."

Belgian historian Jean Vanwelkenhuyzen was quoted by the Austria Press Agency as saying not all of the questions were resolved: "Nothing is definite in history."

But West German panelist Manfred Messerschmidt said the commission had not found anything new that would personally implicate Waldheim.

Waldheim has consistently denied that he was personally involved in war crimes. He first kept silent about his World War II career with the Nazi Army in the Balkans. Later he said he was a minor staff member of the German military high command.

The panel includes military historians from Belgium, Britain, West Germany, Israel and the United States. It was commissioned by the Austrian government last September at Waldheim's request. But when Waldheim learned that its findings might not be to his advantage, he announced he would not be bound by the historians' report.