Former secretary of state Henry A. Kissinger, while teaching at Harvard in 1953, reported to the FBI on anti-atomic-bomb propaganda he found after opening a letter addressed to one of his students, according to an FBI memo obtained by The Nation magazine.

The document, as published by The Nation says that "kissinger identified himself as an individual who is strongly sympathetic to the FBI and added he is now employed as a consultant to the U.S. Army and is a former Cia [Counter - Intelligence Corps] Agent."

Kissinger, through a spokesman and longtime associate, William Hyland, last night described the "implication" of the article, to be published Monday, as "contemptible and ridiculous."

The article, by Columbia University Prof. Sigmund Diamond, suggests that Kissinger's acquiescence to wiretapping while in the Nixon administration was not a matter of the "one-time expediency" referred to in the former secretary's memoirs.

"Kissinger", writes Diamond, "was not a neophyte in the secret scrutiny of his associates."

Diamond, Giddings professor of sociology and professor of history at Columbia, came across the document while researching the relationship between universities and the FBI before and during the McCarthy era.

According to the document, Kissinger told an unidentified FBI agent that he was the executive director of the Harvard summer school international seminar, which invited approximately "40 persons from various foregin countries who, in general, are employed in positions of policymaking level."

The document alleges that Kissinger called the FBI after he opened one of 40 seemingly identical pieces of mail addressed to seminar participants -- specifically, a letter to a person who had not yet registered for the seminar -- and discovered that the letter "was highly critical of the American atom bomb project and set out what purported to represent the shame and anguish of the American population on American preparation for war."

Through Hyland, Kissinger last night said "the accusation about mail opening is absolutely inconceivable."

Asked if the accusation were true, Hyland said: "That's all he'll [Kissinger] say for the record."

Kissinger, according to the FBI memo, "noted that four copies of [a] flyer had been enclosed in the letter . . . and presumed that the person who wrote the letter meant the seminar particpant to distribute the flyer."

The memo dated July 15, 1953, ends by noting that "steps will be taken, however, to make Kissinger a confidential source of this division."

Appended is a copy of the flyer Kissinger allegedly obtained from the envelope.

Hyland last night described the article as "a character assassination thing" and said, "I'm just not going to comment on it anymore."

Opening another person's mail is a federal offense punishable by up to five years in prison. The statute of limitations on such violations is five years.