IN FORMAL INTERVIEWS and informal conversation, Ingred Bergman has been ever forceful and articulate, revealing an intelligence perhaps as rare as her own vibrancy. Talking, she sounds like a writer; and one may suppose that she is ideally equipped for autobiography.

She may be that, and we may never know for certain. Ingrid Bergman: My Story is a fascinating, annoying, irresistible yet ultimately unsatisfactory hodgepodge of a book.

It is a strange and possibly unprecendented sort of collaboration between Bergman and British author Alan Burgess. This is no as-told-to account, nor does Bergman's own prose reek of ghostly assistance -- in which case it would probably be "better" written but artificial.

In all of the 27 substantial "chapters," Bergman and Burgess continually pass the narrative ball back and forth, with neither ever quite running with it far enough. She writes in the first person, he in the third.

She will recall, for example, being in Paris in 1956 for a starring engagement on stage in Robert Anderson's Tea and Sympathy , and will make brief mention of her initial meeting there with Lars Schmidt, destined to become her third husband. There she fades out and Burgess fades in, reporting Schmidt's account of that meeting with Bergman and the beginning of their romance.

Burgess is a one-man Greek Chorus, at times suggesting one of those TV commentators endeavoring to tell us what the president meant in his press conference, after we've heard what the president said . Burgess is always Bergman's spokesman, is too often her cheerleader (she doesn't need one) and sometimes suggests the official apologist that she clearly does not want.

Certainly Burgess' linquistic and reportorial performance is several cuts above standard fan-magazine journalese; but the way the people at Delacorte have put this business together, that seems to be his stsrategic function. Well, it doesn't really work. Time and again we are near to being transported by the Bergman personality and by her admirable candor, then here's Burgess interrupting again, breaking the rhythm, shattering the near-trance.

Beyond any doubt, Ingrid Bergman: My Story will be enormously successful in the marketplace, possibly even surpassing the gaudy commercial returns compiled by Lauren Bacall and Shelley Winters. I suspect, though, that many readers will adopt my habit of reading Bergman attentively and skimming Burgess impatiently, perhaps finally ignoring him altogether.

She's a commanding presence, all right, but the plain truth is that she has a fabulous story to tell. It's a life worth reading about, for its high artistic accomplishment and for its extraordinary real-life romantic and melodramatic appointments.

By 1948 Ingrid Bergman, in American films less than a decade following solid aprenticeship in movies of her native Sweden, had reached a pinnacle of reputation and public favor such as very few stars had ever scaled. She was the foremost international star, and in her euphoria she wrote an impulsive but sncere letter to Roberto Rossellini, the foremost international director of the immediate postwar period.

They made the Stromboli film and fell in love. Scandal of fantastic proportions erupted when they conceived a child, although Bergman was then married to Dr. Petter Lindstrom, by whom she already had a daughter, Pia. That was Ingrid Bergman's fall from grace. Divorced from Lindstrom and eventualy married to Rossellini, she was effectively banished from America.

Later, of course, Hollywood and America forgave and reembraced her. There were more triumphs on stage and screen, more Oscars, and Rossellini was no longer in the picture, although he had given her a son and twin daughters.

Rossellini was portrayed as a rogue in the American press, but it is Bergman's provocative contention that she ruined him.

There was no thought in my mind that I would ever divorce Roberto. I would have gone through hell and still stayed with him, having had such hell to marry him in the first place. Besides I could not leave him because I would have felt I had abandoned somebody that I had been part of ruining. After all, who took the first step? I did."

The Rossellini affair surely has been the central experience of Bergman's life and career, not only in the headlines. Most readers will conclude that he was the great love of her life. She is enormously, refreshingly sympathetic toward him. The Rossellini phase of her life is explored at greater length and in greater depth than the Lindstrom phase, and such attention as is given to Lars Schmidt is only perfunctory.

Feminists will cite Bergman's doll's-house ordeal as wife to the authoritarian Petter Lindstrom, but she is generous and affectionate toward him. Indeed, Ingrid Bergman is without rancor in this memoir, even though she may be entitled to a lot of it. Where "getting even" seems to motivate so many star biographies, Bergman is astonishingly gracious even toward those who were her tormentors.

The people who fill out her book are a casting director's collective dream, but Bergman hardly bothers to fuss about characterization. She expects you already to know that Cary Grant and Alfred Hitchcock are wonderful fellows without having to be told by her. More penetrating is the account of her frustrated attempt to become friends with Greta Garbo, whom she rather pities.

"She was only thirty-five-years old and a most beautiful and talented actress and she never worked again. Can you imagine all those years, and you get up in the morning and what do you do? If you have children and grandchildren that's a different thing. But to be so lonely. . . ."

Memory plays tricks even on Ingrid Bergman, who recalls seeing Garbo at MGM when she was there to made Adam Had Four Sons -- which, however, was a Columbia picture. And some names get misspelled, but editors are supposed to tend to those matters.

Altogether the Bergman autobiographical performance is a responsible one. She adds anecdotal flesh to the bones of the career, and persuades us of her equal dedication to her profession and to motherhood. She gives her life a sense of shape, but shape is a deficiency in her book.