More than a thousand pages of documents released yesterday reveal that during a stormy 40-year relationship, the FBI endlessly examined Frank Sinatra's connections to mob figures like Lucky Luciano and Sam Giancana, sought authority to bug the singer's Palm Springs house and scoured bureau files for dirt that would make him an unwelcome White House guest.

The bureau also rescued Sinatra's son from kidnappers and vigilantly pursued threats against the singer. Sinatra, for his part, deplored the bureau's persistent probes, yet once offered to help FBI Director J. Edgar Hoover catch subversives.

The FBI released the Sinatra files yesterday in response to more than 30 Freedom of Information Act requests filed by news organizations after the singer died of a heart attack in May at age 82. The inquiring media included wire services, newspapers, television networks and programs such as "Entertainment Tonight," according to an FBI spokesman.

Twenty-five pages of the 1,300-page file were withheld to protect confidential sources and methods. Some sections of the released pages were blacked out. Sinatra himself requested and received portions of his file in 1979 and 1980, when the documents were unavailable to the public. When a person dies, the deceased's FBI file can no longer be withheld on privacy grounds.

The newly released documents describe an extremely complicated relationship between Sinatra and the FBI stretching from the 1940s to the 1980s. The FBI also delved into Sinatra's 1938 arrest on a seduction allegation in Hackensack, N.J., and its interest continued through an alleged $100,000 mob extortion plot in 1970. Sinatra was not charged in either incident.

The bureau nosed into Sinatra's mob ties and sifted through allegations that he was a communist. But the agency also saved Sinatra's son by thwarting a dramatic kidnapping, investigated several attempts to extort Sinatra and cooperated in his daughter Nancy's attempt to write a biography titled "A Very Gentle Man."

For his part, Sinatra gratefully thanked the FBI for its help in the 1963 kidnapping case and even offered to become an FBI informant in 1950. But Sinatra never went to work for Hoover. And Hoover and his men, for all their efforts to tie "The Chairman of the Board" to the mob, were never able to do more than document Sinatra's social schedule with unsavory types and ask "The Voice" some pointed questions.

The files, a myriad of details both arcane and bizarre, do not alter the picture of Sinatra as a great entertainer who maintained a lifelong flirtation with the mob and struggled to rein in an explosive temper.

Regarding Sinatra, no detail appeared too small to the FBI. One note, apparently handwritten by Hoover, refers to a clipping about delirious girls waiting in line for a Sinatra concert in 1946: "Sinatra is as much to blame as are the {indecipherable} bobby-soxers -- H."

The accumulation of detail -- comical at times, numbingly mundane for the most part -- serves to deflate the image of Sinatra as a mob associate. For example, the files recount the famed occasion in 1947 when Sinatra greeted Lucky Luciano at the Nacional Hotel in Havana. Rumors have swirled for years that Sinatra accompanied Joseph and Rocco Fischetti, members of the Al Capone gang, as they allegedly carried $2 million in cash to Luciano. But the allegation, like so many others, goes nowhere.

"Bureau sources had revealed no information which would indicate that Sinatra, Sr., was in Havana in 1947 at the time the above mentioned two million dollars was allegedly passed to Luciano, or that he was aware that the Fischetti brothers allegedly carried such a sum to Luciano," an FBI report states.

Sinatra first came onto the FBI's radar screen in February 1944 after a false allegation lodged by gossip columnist Walter Winchell. The last entries came in the 1980s, when the FBI had ceased investigating "Old Blue Eyes" and was more apt to protect him from crackpots writing threatening letters.

Winchell claimed in a letter to the bureau that the singer had paid $40,000 to obtain a deferment from the draft. The G-men dutifully pursued the tip, discovering that Sinatra had been legitimately excluded from military service because of a punctured eardrum.

In the 1940s and 1950s, the bureau's twin preoccupations were reflected in its probes into Sinatra's alleged ties to communists and criminals.

The agency ran down numerous allegations that Sinatra associated with communists or was a member of communist front organizations. But years of checking turned up no hard evidence.

Early in his career as a remarkable vocalist and bobby-soxer heartthrob, Sinatra unabashedly linked himself to liberal causes. But his statements against racial and religious intolerance, and his occasional appearance at rallies in support of those causes, were viewed by some as signs that he was sympathetic to communism.

FBI agents detailed Sinatra's marginal association with organizations considered suspicious, such as the American Crusade to End Lynching and the American Society for Cultural Relations with Italy.

Hoover showed an eager interest in Sinatra from the beginning, as evidenced by marginal notes that appear to be in his hand, signed with the initial H.

"Are the paragraphs marked with ink provable? -- H," says one note, which, elsewhere in the files, an agent confirms was a query from Hoover. The paragraphs detailed Sinatra's alleged connections to communist-related groups.

But in later years, Hoover proved eager to protect Sinatra from investigators. The request to bug Sinatra's Palm Springs, Calif., residence came in April 1963. "LA requests authority to conduct a survey to determine feasibility of misur in Sinatra's Palm Springs residence," an FBI document states. "Misur" is microphone surveillance. The request referred to Sinatra "as a possible front for investments for hoodlums of both national and international stature."

Hoover denied the request. "Los Angeles should take no action whatever which could be interpreted as investigation of Frank Sinatra," the director responded.

The mob-related portion of the files repeatedly returns to Sinatra's enduring relationship with Chicago mob boss Samuel Giancana, described as "a cold, brutal killer" who assumed leadership of the syndicate in Chicago in 1956.

"Giancana has been a guest at various places owned or operated by Sinatra and at Sinatra's home in Palm Springs, California," one FBI report states.

The files note that Sinatra in the late 1940s and 1950s associated with a number of well-known mobsters, including the Fischetti brothers; Bergen County, N.J., mob boss Willie Moretti; and James Tarantino, a onetime associate of Los Angeles mobster Bugsy Siegel.

In 1964, an informant told the FBI "that although Sinatra was not a member of the syndicate, he was big enough and close enough to the organization to obtain any favors he desired."

That same year, another informant said Sinatra owed the syndicate "a lot of money" and had secretly maintained his financial ties in gambling establishments in Nevada. Earlier, he had promised authorities in the state that he would give up his interest in a Lake Tahoe casino after he was seen entertaining Giancana there.

The files make no mention of Judith Campbell Exner, the woman Sinatra introduced to both President John F. Kennedy and Giancana. And Kennedy himself figures into the documents in only the most fleeting, tangential manner.

But files show that the White House maintained an interest in Sinatra's FBI file long after JFK was killed. In November 1964, Bill Moyers, then special assistant to President Lyndon B. Johnson, was given "a summary of information on Sinatra and other entertainers."

In August 1967, the FBI responded to a request from the White House for an updated review of information about Sinatra.

"Our files reveal that Frank Sinatra continues to associate both socially and on a business basis with alleged members of La Cosa Nostra and other members of the hoodlum element," the FBI response states.

Mob meetings in South Florida are alleged to have occurred simultaneously with Sinatra concerts at the Fontainebleau Hotel in Miami Beach, according to the FBI's informants.

The files create the overwhelming impression that Sinatra could not escape his mob ties, no matter how far he traveled from his New Jersey roots. One informant in the late 1960s claims that "anything that Sinatra does, Giancana is a part of it." Sinatra, the informant states, was originally "brought up" by mob boss Frank Costello of New York.

In 1950, Sinatra sent an unnamed intermediary to seek an audience with Hoover, offering Sinatra's help as an informant in the entertainment world. The FBI said the intermediary conveyed Sinatra's concern about the allegations against him, as well as the singer's desire to help the bureau. The go-between never got to see Hoover, and a deputy agent was noncommittal.

Later, at the bottom of a report on the visit, Hoover's top aide, Clyde Tolson, scrawled: "We want nothing to do with him." Below that is the inscription: "I agree -- H."

Fourteen years later, after the FBI worked to solve the kidnapping of Frank Sinatra Jr., a deputy proposed to Hoover that the bureau might be able to get Sinatra to spill secrets about alleged mob contacts.

"I do not agree," Tolson scribbled at the bottom of the proposed plan. The next note says: "I share Tolson's views -- H."

After all the years of investigation, Sinatra wrote at least one "Dear Edgar" letter to Hoover, in July 1964, after the kidnapping episode.

"I would like to express my deep appreciation and thanks for the excellent work of the FBI in securing the safe return of my son, in solving the crime, and for the tremendous amount of work I know they did in assisting the Department of Justice in prosecuting the crime." CAPTION: Included in the FBI's newly released file of nearly 1,300 pages are mug shots from Frank Sinatra's 1938 arrest on a seduction allegation. ec CAPTION: In a September 1976 photo taken in New York, Frank Sinatra, second from left, poses with, from left, Gregory DePalma, Thomas Marson, Carlo Gambino, Jimmy "the Weasel" Fratianno and, seated, Richard "Nerves" Fusco. ec