"Heaven Can Wait" is easily the most appealing new American movie on the market. It manages to preserve much of the charm and romantic fantasy that worked for its predecessor, the 1941 crowd-pleaser "Here Comes Mr. Jordan," while freshing up some of the settings and details and tailoring the roles to a different cast.

Robert Montgomery starred in the earlier film as a promising prize-fighter named Joe Pendleton who was robbed of a shot at the title when an overzealous angel, Edward Everett Horton, snatched him prematurely from an apparent rendezvous with death. Aided by a sympathetic divinity-in-chief, Claude Rains as Mr. Jordan, the hero eventually found another human form to shelter his disembodied spirit.

Warren Beatty assumes the Joe Pendleton role in the remake, which depicts Joe as a quarterback with the Los Angeles Rams. Buck Henry, who shares a co-directing credit with Beatty, appears as the hasty heavenly escort, James Mason has inherited the role of Mr. Jordan, which was turned down by Beatty's cunning first choice, Cary Grant.

The original plot remains intact. Joe returns initially in the fast-sinking body of a wealthy playboy named Farnsworth who has been drugged and left in the bathtub by his wife and private secretary, adulterous conspirators played with brilliance by the surprise comedy team of Dyan Cannon and Charles Grodin.

Cannon's jumpiness in the presence of her husband after his startling recovery is especially funny. Each time Beatty approaches her, she seems to leap out of her skin or drop somthing breakable. Grodin suggests a sinister Charlie Brown. he's the blandest-looking sneak who ever skulked across the screen. Together, Grodin and Cannon become a comic version of Lord and Lady Macbeth.

The bodyof Farnsworth brings Joe into contact with Betty Logan, portrayed by Julie Christie, who bowls him over and encourages him to reform Farnsworth character. The self- centered, ne'er-do-well Farnsworth of old changes almost overnight into a generous, public-spirited fellow, given to impulses that worry the directors of the companies he owns.

Obsessed with returning to the Rams and playing in the Super Bowl, Joe engineers a try-out and then buys the franchise for good measure. Since his wife and secretary persist in their homicide attempts, destiny eventually forces him to vacate the body of Farnsworth. He finds another body just in time to star in the closing moments of the Super Bowl and to renew contact with Betty before the fadeout, which promises the beginning of an uninterrupted love match.

It's the first time that Beatty has wooed Christie successfully on the screen. In "McCabe & Mrs. Miller" she walked out on him. In "Shampoo" she walked out on him. Now that she walks off with him, it's as if we'd been waiting a lifetime for such a sweet switcheroo.

At the outset Joe seems even more naive and boyish than the character Beatty played in "Shampoo." And in his first scenes with Christie, Beatty seems to be at a disadvantage. Christie's flinty, incisive acting style makes his halting, puzzled boyishness look intolerably slow-paced and slow-witted.

Beatty won me over in the course of a cleverly written and delivered both the decency and enthusiasm in Joe assert themselves. It's the pep talk of a cagy, likeable moderate, and is punctuated with allusions to be crusading activities of the actor's friends and relatives, notably the save-the-porpoises campaign once spearheaded by the screenwriter, Robet Towne. For the first time you believe in Joe's leadership qualities and in his sense of destiny.

The fact that Joe's destiny includes a Super Bowl triump for the Rams should prove a rich source for satire among sportswriters. It can only be a matter of time before some caricaturist envisions George Allen in a costume inspired by the winged sweatsuit Beatty wears in the literally heavenly logo for "Heaven Can Wait."

Out of some curious whimsy Christie has been costumed in tweedy outfits. It's difficult to tell if Theodora Van Runkle intended to set an unflattering new style or underline the fact that Betty Logan is supposed to be English. At any rate, Christie's acting and facial expressiveness haven't gone tweedy. She's a riveting sexual presence, blessed with one of the most eloquent smiles in movie history.

Production designer Paul Sylbert and set director George Gaines appear to deserve special thanks for the flower-crazed motif of Dyan Cannon's boudoir. But "Heaven Can Wait" lacks the finishing stylistic polish that a sophisticated and experienced director exercising clear authority might have contributed. There are slack passages and missed opportunities for intensified suspense and romance that might be traced to the lack of a unifying eye and sense of timing.

After "Hot Tomorrows," the notion of The Beyond in "Heaven Can Wait" seems musty and outmoded, but most people will feel more content within these old-fashioned cloudy panoramas. The material evokes kinds of wish fulfillment that are virtually irresistible: the belief in a benign providence, the power of invisibility, the satisfaction of suddenly enjoying wealth and influence and using them magnanimously, winning the big game, the promise of a destined, ideal romantic partner.

The fairy-tale quality may give the film a special, reassuring appeal for childrean, but at some level one never ceases believing in the kinds of fantasies this story weaves into a single, entertaining unit. "Heaven Can Wait" is a pleasurable dream world to slip into and out of.

The most curious piece of casting is Buck Henry in Edward Everett Horton's old role. Needless to say, Henry cannot step into those highly specialized shoes. On the other hand, one can imagine Charles Nelson Reilly bringing a fresh interpretation to the basic personality type. Even Paul Lynde under suitable restraints.

"Here Comes Mr. Jordan" remains a durably enjoyable movie. "Heaven Can Wait" doesn't improve it in any fundamental way, but in this season of misbegotten spin-offs and spoofs, it's refreshing to see a new picture that understands and respects the sources of its inspiration.