The FBI once paid for newspaper subscriptions for top American Communists, talked of helping elect an informant as Imperial Wizard of the Ku Klux Klan, and apparently served as the primary distributor of "Black Panther Coloring Books" that depicted the police as saber-toothed pigs.

For several years, FBI agents even reached across the border - in tightest secrecy lest the CIA or anyone else find out - to conduct covert operations against the Mexican Communist Party. Surreptitions attacks on other targets were occasionally couched in language so coarse that the contents were marked "Obscene" before submission to FBI Director J. Edgar Hoover.

The FBI operations, all part of a long-lasting campaign of disruption and dirty tricks against those deemed subversive, were laid out in unprecedented detail yesterday with the release of 52,648 pages from its so-called Cointelpro (counterintelligence program) files.

The 15-year campaign was ordered discontinued in 1971. But according to an FBI memo dated the day before the cutoff order was handed down, the primary reason was "to afford additional security to our sensitive techniques and operations." The Senate Intelligence Committee cautiously reported last year that it had uncovered three instances of "Cointelpro-type" actions after the cuttoff date and simply had not been able to determine with any greater precision whether they might be continuing.

The massive compilation of documents released yesterday added many new details and some new operations to what is already public record, but they were still heavily censored. Another 16,346 pages also sought for the past three years by reporters and others under the Freedom of Information Act, were withheld completely.

The records reflect a stunning range of disruptive techniques, a constant drumbeat of bureaucratic and peer pressures to show results and a steady source of unquestioning allies in the press who could be fed a wide variety of discomfiting rumors and reports.

Not a few of the suggestions came from Hoover, who had an eye for detail. On Aug. 5, 1965, he suggested that FBI agents approach the New York State police to see if they might "accidentally" intercept Communist Party leader Gus Hall for a minor traffic violation while vacationing in Clifford's Falls, N.Y. (There was no indication of whether this was done).

For the 1966 Communist Party national convention, the director told the New York City office that "uncomfortable" odors might be introduced through the cooling system and that the power in the hall might be shut off completely on the last day of the convention.

For the KKK, the documents included a proposal to depose Imperial Wizard Robert M. Shelton of the United Klans of America by means of a "smear campaign" depicting him as afraid to call a national klonvocation for fear it would vote him out of office.The strategy was to goad Shelton into calling the klovocation, where the ubiquitous FBI would arrange to have him removed.

"Our objective," according to one memo, "would have been the establishment of an informant or a subject controlled by a bureau informant as UKA imperial wizard."

FBI headquarters rejected the scheme in 1976 - on grounds that the bureau already had an adequate network of klan informants.

Other records seemed to bear out the old saw that the FBI was at the core of not a few "subversive" cells. In one of the incessant progress reports demanded by FBI headquarters, the special agent in charge of the Mobile, Ala., office wrote:

"As previously noted the only Black Nationalist organization active in this division is the YOuth Progressive Committe in Montgomery, Ala., eight, two of whom are informants."

For the New Left, the harassment included a variety of disruptive tactics such as a 1970 flyer aimed at the New Mobilization Committee Against the War In Vietnam. Depicting one sneering duck atop another under the headline, "Fly United?" the flyer assailed what it said was "the crap influence" in the New Mobe of the Socialist Workers Party and "its bastard youth group - the Young Socialist Alliance."

A copy was submitted to Hoover with the apologetic notation, "The enclosed has been marked 'Obscene' because of its contents. The copy program on the leaflet has been written in the jargon of the New Left, necessitating the use of a certain amount of porfanity."

The first Cointelpro began in 1956 with a patriotic flourish. On Aug. 22, William C. Sullivan, assistant to the director, turned in a memo tsating that "The Communist Party, USA, today is in a state of confusion and fluster and division." He went on to propose a thorough study of the party and its various factions which could "serve as a type of text or guide or source book for carrying out a program of disruption."

The origins of th "Black Panther Coloring Book" are murky, but it seems first to have come to the FBI's attention in early June of 1969. Hoover deemed it worth exploiting if the FBI could "determine whether Black Panther National headquarters is responsible" for the book, which depicted black children enthusiastically killing police officers.

The coloring book was the centerpiece on June 24, 1969, at a hearing before the Senate Permanent Investigations subcommittee. A Panther spokesman later accused a renegade member of printing the books without permission, and a priest at a Catholic church in San Francisco where some copies were distributed accused police of circulating far more. The FBI was still surreptitiously handing them out months later, including copies for church and women's gorups where the Panthers were seeking funds.

An FBI official defended the often bizarre suggestions by field offices: "Once you make it a program, with required reports every 30 or 90 days, you've got to cime up with ideas. And there just aren't that many around. So sometimes some agent would go bananas, or oranges."

The oranges reference was to a November, 1970, suggestion by the Newark field office that a mild laxative be injected by hypodermic needle into a shipment of oranges being sent to the local Black Panther headquarters. The idea, besides making the recipients ill, was to make the Panthers afraid to accopt free food from supporters.

Headquarters in Washington rejected the proposal, an answering memo said, only because the FBI could'nt control the shipment of the oranges.

The Newark field office, about the same time, also suggested that a "foul-smelling" chemical called Skatole (C9H9N) be sprayed on the shipment of Black Panther newspapers to "disrupt distribution." That proposal was also turned down.

The internal memos constantly refer to using "friendly" members of the press to get the FBI message across.

In October, 1970, the Miami field office suggested that false information be passed to a "cooperative staff writer" on the Miami Herald to imply that a local man had furnished the government with information leading to the arrest of Angela Davis.

Headquarters rejected the idea, not because the information was false but because it had "no great benefit" to the FBI.