Fifteen years ago, Noel Coward suggested that Elizabeth Taylor and Richard Burton should costar in ''Private Lives,'' a 1930 comedy that prompted The Times (London) to note Coward's ''unsurpassed gift for combining entertainment with nothingness. . . .'' The Coward idea has come to fruition at the Lunt-Fontanne Theatre - whether too belatedly may be a matter of critical opinion.
In popular terms, there is no argument. The once audacious piece of frivolity opened to an advance ticket sale of more than $3 million. Whatever else it signifies, the venture is a tribute to the drawing power of its stars, abetted by shrewd showmanship and calculated commercialism.
Miss Taylor and Mr. Burton play a divorced couple who turn up at a Deauville hotel, each with a new spouse. Under the spell of moonlight and ''Some Day I'll Find You'' by an unseen orchestra (''Extraordinary how potent cheap music is,'' says Miss Taylor as Amanda), the ''ex''-es fall for each other again. They decamp to Paris, followed in fairly short order by Victor (John Cullum) and Sybil (Kathryn Walker), the mates they have impetuously jilted.
''Private Lives'' demands a light touch, a crisp manner, and a firm grasp of Coward style. As staged by Milton Katselas, the production at the Lunt-Fontanne tends to be broad and considerably less than mercurial. Nevertheless, the Friday preview audience found ample grounds for laughter, applause, and general enjoyment in the Coward-y shenanigans. Mr. Burton plays Elyot with implacably dry humor and comic aplomb, while Miss Taylor romps through the role of Amanda with disarming cheerfulness. Mr. Cullum and Miss Walker grapple as best they can with the roles of the bulldogged Victor and undeservedly miserable Sybil. Helena Carroll's French maid faces the morning-after shambles of Amanda's flat with Gallic expostulations.
The spectators' response to the revival occasionally betrayed an element of voyeurism. This is no doubt attributable to the fact that the principal onstage couple were being acted by two stars whose much-publicized private lives have included being twice married to each other and twice divorced. Further to express their appreciation, some fans popped their camera flash bulbs from time to time to snap what they considered an irresistible moment. The cast took it all in stride.
In terms of design, ''Private Lives'' appears to reflect a melange of tastes. David Mitchell's terrace and apartment settings (lighted by Tharon Musser) attractively serve the needs of Coward's antic dialogues and farcical pillow fights. The costumes by the usually irreproachable Theoni V. Aldredge include a wardrobe for Miss Taylor that looks as if it had been dreamed up for a masquerade party. In a sense, the revival as a whole adds up to something of a masquerade.