A U.S. Army intelligence operation accumulated information on about 18,000 American civilians before its activities were stopped in 1969, the New York Times reported yesterday.

Investigative activity focused on "radicals, black militants and dissenters against the war in Vietnam," the article stated.

The operation began, following the 1965 ghetto riots and early anti-war protests, as a casual adjunct to the activities of Army agents engaged in making security checks. But by 1969, intelligence activity was turning up 1200 spot reports a month on incidents occurring around the country, according to the Times.

The extent to which the Army monitored activity at Harvard is unclear. Army officials at Fort Devens, Mass., where headquarters for the 108th Military Intelligence Group are located, referred inquiries to the Army Intelligence Command at Fort Holabird, Md. It was not possible to reach anyone at Fort Holabird yesterday for comment.

But the author of the Times article, Richard Halloran, said yesterday that the 108th-which monitored the northeastern U.S.-was one of the most effective in the intelligence operation.

An official at the FBI's Boston office who refused to identify himself stated that his office had no comment to make on its role in the operation.

The Army stored its accumulated data in computers, the Times noted. Its information came largely from local police departments and the FBI, but Army agents added to the files by conducting investigations on their own, sometimes joining the groups they were investigating.

For a time, the Army circulated "blacklists," which contained names and pictures of individuals it identified as "dangerous," the Times stated.

Army officials ordered information in its computers destroyed last February, after a magazine article revealed the nature of their operation to the public, the article stated.