"Close Encounters of the Third Kind," the extraordinary new science-fiction fantasy created by Steven Spielberg, begins as a kind of "Jaws" from the heavens, provoking a considerable amount of thrilling anxiety about the appearance of Unidentified Flying Objects. It must weather some bummy mid-passage exposition, but the movie survive its flaws triumphantly, evolving into a uniquely transporting filmgoing spectacle.

Spielberg, prodigiously gifted and resourceful, has contrived to bestow a dazzling benediction on fellow star-gazers. He transforms the ongoing, somewhat forlorn mystery of UFOs into a transcendent fairy tale vision of intergalactic communion and fraternity.

An exciting and beguiling act of creative wish fulfillment. "Close Encounters" depicts a sequence of events culminating in authenticated, face-to-face contact between human beings and humanoid extraterrestrials. During the brilliantly sustained finale which documents this contact. Speilberg puts on an enchanting magic show, springing one sensuous and sentimental highlight after another.

There are poignant homecomings and departures, a stunning display of flying ability and aerodynamic technology from a versatile fleet of spaceships, and a giddy jam session between a color-coded moog synthesizer operated by the hosts and a blaring, glittering space leviathan, the majestic flagship of the visitors. It's as if Spielberg had synthesized his favorite things about planetarium shows, air shows, half-time ceremonies. Helloween, Christmas and classical, jazz and pop concerts into a single gala entertainment.

"Close Encounter" ends up on a crescendo of pictorially awesome, sentimentally reassuring affirmation. When that incredible flagship sails away, audiences are meant to savor the illusion that they must be going to heaven on the wings of the snazzies advanced technology in the universe.

Some movies generate a keener sense of anticipation than others. Being keenly anticipated also creates the hazard of proving an acute disappointment. Exposed to an excess of hearsay from people who claimed to have seen the film in whole or part. I began getting rumor shakes. The climax came one night when I dreamed that I attended two previews of "Close Encounters," one a triumph and the other a disaster.

Later I discovered that several equally anxious, movie-demened friends had conjured up the same dream. After seeing the picture itself, peace of mind returned. "Close Encounters" wasn't the perfect, ultimate spectacle we may have secretly longed for, but that was more our problem than Spielberg's failing. It was still a fascinating, stirring flight of fancy, destined to linger in the memory and occupy a special and perhaps influential place in the history of the S.F. genre.

Spielberg's visual flair and youthful gusto have appealed to me from the opening shot of "The Sugarland Express." There's no point in pretending to feel impartial about his work. I look forward to it, and I would hate to see him blow a big one. From the outset Spielberg has seemed the most energetic, convivial and visually inventive of our young filmmakers. On the eve of his 30th birthday he has now completed four features, counting the television thriller "Duel," that must make him the envy and inspiration of every movie-loving, movie savvy kid in the country. Hovering Humor

Spielberg has constructed the story as a suspense thriller in which parallel sets of UFO seekers race toward a climatic confrontation. An expedition led by a French scientist named Lacombe, played by Francois Truffaut, arrives at a desert location in Mexico. While shouting through a raging sandstorm, Lacombe and his colleagues discover and test a squadron of torpedo bombers that vanished 30 years earlier.

The planes are in perfect condition. A stunned old man who may have witnessed the mysterious return claims that "the sun came out and sang to me," Like the remark "You're gonna need a bigger boat" in "Jaws," the old man's apparently crazed statement proves to be sensible.

The scene shifts to Indianapolis, where air traffic controllers monitor a near collision between a passenger plane and a UFO on their radar screens. At a country house outside Muncie a little boy named Barry Guiler (played by a winsome 4-year-old, Cary Guffey) is awakened by a warm breeze and a flurry of activity among his mechanical toys. His mother Jilliam (Melinda Dillon) gets up to find toys running amuck and her child gleefully running away.

Finally, a power company lineman named Roy Neary, played by Richard Dreyfuss, is summoned from an evening at home in the Muncie suburbs with his wife, Ronnie (Teri Garr)., and their three kids. While assisting in the emergency work caused by a sudden, inexplicable power failure, Neary undergoes a form of illumination that totally disrupts and alters his life.

Lacombe heads a team trying to arrange a discredit rendezvous with extraterrestrials, provided the visitors' apparent clues and signals can be interpreted correctly. Neary is one of several ordinary people whose brush with a UFO has resulted in an obsessive version of the eventual meeting site, a sheer, truncated peak in Wyoming called Devil's Tower.

Spielberg is a dynamic director, but the emphatic technical cleverness and virtuousity at his command are expressed in surprisingly agreeable ways. His vigorous imagery and bustling, incisive editing rhythms quicken one's expectations to begin with, yet they're intensified by a playful and often breathtaking sense of humor.

"Jaws" was, of course, a triumph of humorously augmented terror, a scare thriller rendered more thrilling by Spielberg's uncanny comedy timing, his ability to juxtapose frightening and funny sensations. A choice example occurs in "Close Encounters" when a house is being probed by a UFO energy source, which activates all the appliances, including a record player. Just as you're losing your composure, along with the householder, the following phrase from Johnny Mathis' "Chances Are" croons from the record player: "Just because my composure sort of slips, the moment you come into view . . ."

The first appearance of a UFO is a wonderful visual joke based on the first appearance of the shark in "Jaws." Dreyfuss is discovered lost at a railroad crossing on a country road. Absorbed in studying a map, he fails to notice the remarkable thing that happens when headlights illuminate his back window and he signals the vehicle to go around, as an earlier vehicle did moments before.

Neary is jolted out of his obliviousness when that second vehicle turns on its high beams. The audience is jolted too, especially if the film is being shown with Dolby sound, which rocks the theater as effectively as Sensurround. Being allowed to see something coming enhances the sensation by encouraging spectators to scare themselves into the appropriate mood for the payoff. Audience Sightings

Spielberg relied on identical audience participation in "Jaws." His basic approach in "Close Encounters," extending to the film's visual scheme, consists of letting the audience see something apprehensive approach or astonishing occur that is ultimately revealed to be less threatening than feared. Unlike some directors with an affinity for terror. Spielberg is considerate of his audience. He wants us to feel pleasurably shaken up. The most amusing and likable specialist in terror since Alfred Hitchcock in his prime, Spielberg knows instinctively how humor and reassurance may simultaneously relieve and intensify apprehension. Seconds after rocking the theater he teases the audience with a diminished shock effect - the hero scaring himself with his own flashlight.

Spielberg seems to be whispering, "This is going to scare you, but don't be afraid." The message is reflected in the face of little Barry when his expression shifts from perplexity to delight during a sudden encounter with unseen, luminous presences, who evidently become his playmates. Spielberg treats filmmaking itself as play - technically sophisticated, or course, but still play. One can feel the pleasure he derives from the filmmaking toys and playmates at his own disposal. Too-Brief Encounters

The plot begins to wear thin during the middle reels, when Neary spooks his family with erratic behavior and then struggles to reach Devil's Tower, where Lacombe's team is laying out the welcome mat while assiduously camouflaged by the military. Neary's domestic breakdown was dramatized in more detail in the original screenplay. Spielberg shaves it precariously close in the film, ditching scenes that leave abrupt transitions and insufficient explanations in their absence.

For example, Neary gets fired without an explanation. Originally, he had abandoned an assignment in order at chase mysterious lights across the countryside. In the film this sequence of events is so compressed that we can only guess that he might have been derelict in his duties. Originally, Spielberg depicted Neary beginning his grand work of creative nuttiness - a giant replica of Devil's Tower inside his house - after he was given up for crazy by his panicked wife. Now she feels as a consequence of this stunt, which looks more exhibitionistic than desperate, robbing Neary of a sympathetic motive for making a shambles of his home and marriage in pursuit of his vision.

There's more fundamental problem. Neary's family life seems too perfuntory to stir serious pangs about his compulsion to seek high adventure. The Roy Scheider household in "Jaws" had more conviction, maybe because that family man was expected to return from the unknown. Nothing about Teri Garr's Ronnie makes the thought of separation difficult to bear.

Spielberg doesn't heat up anything between Neary and fellow seeker Jillian either, although he appears to imagine that he has. It might have helped to show them traveling together from Muncie to the vicinity of Devil's Tower, instead of meeting by coincidence in the midst of a throng of evacuees.

Spielberg is never boring, but at times he moves too fast for clarity or skirts obligatory scenes. Even when the dramatic footing is soft, he's tempted to gun the motor, producing a commotion, but not always headway of a necessary kind. This is the negative side of dynamism.

"Close Encounters" could use more intimate summarizing and stock-taking interludes. "The Sugarland Express" and "jaws" benefitted from them, and they could have been especially useful to establish emotional bonds between Truffaut's trained star-gazers and expectant space pilgrims and the pixilated intruders represented by Dreyfuss.

Spielberg sustains a conventional chase situation, with recollections from "North by Northwest" and "Lonely Are the Brave," long after it outlives its justification. Instead of playing extended hide-and-seek with the military, Neary and the other crashes should be allowed to participate in the welcome on the authority of generous, sympathetic Lacombe. Spielberg remains too loyal to conventional plot devices to junk them as soon as he should. A Lucky Star

One grows a little impatient for the resolution, but when it arrrives, all is forgiven. "Close Encounters" represents the fulfillment of Spielberg's own longing and speculation about UFOs, which have intrigued him ever since he missed a Scout trip where the great event was a sighting. Much of the film's charm drives from Spreilberg's sophisticated exploitation of what is acknowledged to be a childlike sense of wonder and adventure. This is the most sophisticated of navie movies.

Cary Guffey seems to stand in for the filmmaker as a child, just as Dreyfuss and Truffaut illustrated his grow-up susceptibilities. However, the Truffaut character and his colleages - especially Bob Balaban's shy, earnest translator-cartographer, who resembles the Dreyfuss character in "Jaws" - would probably have made more congenial alter-egos for Spielberg than average-guy Neary, presumably considered a must for mass identification but a banal archetype to begin bodied by an actor as unconventional with and a shakier one when emas Dreyfuss.

Spielberg's film could stir unexpectedly deep longings for adventure and heroism. It seems to have a particularly strong effect on solitary, imaginative people who feel a bit stymied or wasted in their jobs and might not hesitate to sail away to distant civilizations.

At its first preview in Dallas the film's concluding images were accompanied by the original recording of "When You Wish Upon a Star" from Walt Disney's "Pinocchio." The reference is now indirect. The hero's wife teases him with the nickname Jiminy Cricket. A children's music box with molded figures of Pinocchio and Jimmy plays the song. Composer John Williams, who won an Oscar for "Jaws" and probably sewed up another months ago with "Star Wars," weaves the melody of "When You Wish Upon a Star" into an elaborately orchestrated celestial finale.

The celestial effect is justified, but it's also worth recalling that the Ned Washington lyrics, which were quoted in Spielberg's original screenplay, appear in his novelized version and remain crucial to his conception. These are the key lines:

If your heart is in your dream.

No request is too extreme,

When you wish upon a star

As dreamers do.

Fate is kind;

She brings to those who love

The sweet fulfillment of

Their secret longings.

What Spielberg has achieved is a sweet imaginary fulfillment of the longings for verified extraterrestrial contact, universal fellowship and heroic endeavor felt to varying degrees by UFO freaks, armchair explorers and contended but diversion-seeking homebodies. Attaining this sweet fulfillment required two years of production and cost a bundle - about $20 million, perhaps as much as 80 per cent representing expenditures for special effects, with another $6 or $7 million appended for mass advertising.

It also required the collaboration of an army of designers, craftsmen and technicians, notably the special effects wizard Douglas Trumbull, who can take special pride in his flying saucers and the unearthly grandeur of their swirling protective cloud formations. Spielberg worked with five illustrious cinematographers; Vilmos Zsigmond, William Fraker, Douglas Slocombe, John Alonzo and Laszlo Kovacs. Again, the lyrics of "When you Wish Upon a Star" apply: No request is too extreme and no expense should be spared when there's a chance of enhancing a movie spectacle with the legend-making and money-making potential of a "Close Encounters."

Like George Lucas in "Star Wars," Spielberg in "Close Encounters" celebrates modern technology in a way that may reflect and hasten changes of sentiment in the American public. There is no fear of technology in either filmmaker. On the contrary, each appears to believe that the movies, the most mechanically dependent of arts, can be used to affect a mythic reconciliation between humanity and technology.

"Close Encounters" and "Star Wars" are outward-bound visionary entertainments. Their receptivity to the future, including fancied technologies of the future, may be naive in a certain respect, but it also reflects a fundamentally healthy, courageous, youthful outlook.

Spielberg's finale is beautifully organized and visualized, with the spacecraft materializing from the heavens to cavort like otters and top their own toppers, so that a fresh assortment of pictorial delights is passing constantly in review. However, the most impressive sight is undoubtedly the appearance of the flagship, which suggests a gigantic illuminated chandelier or oil refinery. When this fantastic flying machine looms into view, you think, Uh-oh, they better be friendly because that's some kind of technology they've got out there.

Again, Spielberg allays the fear. This airborne monster flashes brilliant teeth, but it doesn't bite. The occupants look spindly and nebulous but also plaintively human in expression. They remind you of little Barry at his first encounter, receptive to friendly overtures.

These aliens seem to emerge from the dreamworld of an idealistic and precocious child. Despite their technological superiority, they want to make friends, be a force for good . The first movies speilberg was permitted to see were Disney classics, and he has absorbed Disney's influence in a far more creative and affecting way than most of the people now producting films for the Disney studio. He ought to be invited to collaborate with their better young animators on a fantasy combining live-action and animation.

Columbia can thank its lucky star that Spielberg came through. People who believe in UFOs may also regard "Close Encounters" as a vindication, but it may have made the reality of UFOs irrelevant. Speilberg has transmitted a glorious greeting. If extraterrestrials exist and fail to respond, they obviously aren't movie lovers, have no romance in their souls, and to hell with 'em.