The stage version of the delightful 1958 Lerner and Loewe film "Gigi" has pulled into the Lyric Opera House here for a holiday engagement that is likely to inspire a loud chorus of ho-ho-ho-hums. This may well be the why-bother project of the year -- one of those conversions from celluloid to flesh that, ironically, not only fail to capitalize on the presence of three-dimensional actors, but actually suffer an alarming loss of vitality for being, as they say, live and in person.

Mounted for a countrywide tour by the triumvirate that runs the Harlequin Dinner Theatre in Rockville, the production stars Louis Jourdan as that charmingly aging roue' Honore Lachailles, a role made memorable in the film by the late Maurice Chevalier.

But whether it's out of nostalgia for the sound track, or simple fear of singing before a paying public, Jourdan lip-syncs his two biggest numbers in the show. The tactic is not calculated to promote the overall spontaneity of the evening.

Jourdan is also a veteran of the film -- he played Gaston, the bored, young man about Paris, who tumbles for gauche, gaminlike Gigi. And it must have struck someone as the casting coup of the season to bring him back, lo these many years later, and bump him up into the older part. Granted, he looks swell at 63 and spectators of a certain age gasp audibly at his first entrance. His body is trim, and trimly outfitted in turn-of-the-century suits. If his face has the mobility of frozen yogurt, his features remain classically Gallic.

But that's one of the problems. When he takes the stage in the second act to mouth the words to "I'm Glad I'm Not Young Anymore," you won't believe him for an instant. It's like Rockefeller singing "Brother, Can You Spare a Dime?"

Let him team up with Taina Elg -- she has inherited the role of Gigi's grandmother from Hermione Gingold -- for "I Remember It Well." That sweetly touching number, you may recall, has her gently correcting his befuddled memories of their long-ago love affair. But Jourdan suggests little of the poignancy or frailty that would make it work. And Elg comes over as a benevolent schoolmarm.

With the exception of former Arena Stage actor Tom Hewitt, who is an appealing and forthright Gaston, none of the casting compensates for the deficiencies of a script that rarely acknowledges the particular demands of the stage. The musical numbers don't build, they fade out. The plot, thin to begin with, dawdles along for a whole act before it occurs to Gigi's grandmother and her Aunt Alicia (Betsy Palmer) that maybe, just maybe, Gaston is falling in love with their charge and that a lucrative arrangement could be struck. Whereupon Jourdan appears blithely to announce an intermission.

Palmer is grievously miscast as the former cocotte who "has changed hands more often than Alsace-Lorraine." Tutoring Gigi in the ways of the world, the need for fine jewels and the properties of a good cigar, she is about as French as an Iowa cornfield. And Gigi herself, as played by Lisa Howard, is hardly a "little girl" to thank heaven for. She is a big, galumphing girl, and kicking her leg up in back of her coltishly, as she does, doesn't alter the impression for an instant.

To watch this stage version, which has a sparsely populated chorus and no compensatory production numbers, is to realize how much the film depended for its success on the personalities of its original stars. While the Lerner and Loewe score is a durable one, it is several pegs down from "My Fair Lady," which it echoes rather too closely for comfort. That Lerner and Loewe specialty -- a character debating with himself musically -- reached its apogee when Rex Harrison alternately admitted he was just an ordinary man, then cursed himself for ever letting a woman into his life. "Gigi" employs the device repeatedly, to far less dramatic effect.

If the film had the authenticity of its Parisian locales -- Maxim's chief among them -- the stage production, designed by Jeffrey Schneider, relies basically on an Art Nouveau bridgework, enhanced by changing backdrops. It looks fancy as all get-out on first view, but soon reveals itself for what it is: A bus-and-truck set struggling to be lavish, the way a woman with one evening gown in her wardrobe tries to dress it up with a piece of costume jewelry one night and a boa the next.

Dallett Norris is responsible for the lackluster staging, Dean Brown has done the costumes and Hampton King handles the musical direction, including, one presumes, the task of getting the tape of Jourdan's singing voice rolling at the appropriate moments. Although it might be thought that they have graduated to the big time, they have all done far more astute work on the tiny stage of the Harlequin Dinner Theatre.

Like Jourdan, who is becoming a walking mannequin of charm, this "Gigi" is as empty as a magnum of champagne on New Year's morn.

GIGI. Books and lyrics by Alan Jay Lerner. Music by Frederick Loewe. Based on a novel by Colette. Directed by Dallett Norris. Sets, Jeffrey Schneider; costumes, Dean Brown; musical direction, Hampton King; lighting, Brian MacDevitt. With Louis Jourdan, Betsy Palmer, Taina Elg, Tom Hewitt, Lisa Howard. At Baltimore's Lyric Opera House through Jan. 5.