One of the most celebrated couples in film history, Jean-Louis Trintignant and Anouk Aime'e, are back together as "A Man and a Woman -- Twenty Years Later."

The two were were last seen walking hand in hand on the beach at Deauville in Claude Lelouch's 1966 film romance, both recently widowed in their midtwenties, and clearly deeply in love.

But the woman's memories of her late husband were too strong to allow the man to make love to her.

It turns out that relationship ended shortly after the final credits, leaving only the theme tune to be sha-ba-da-ba-dahed by millions around the world. Now the stars of the biggest box office success the French cinema ever produced have found each other again.

"Everything has changed -- except their love," shout the billboards at Cannes, where "A Man and a Woman -- Twenty Years Later" had its premiere this week at the annual film festival.

Trintignant has grown a beard and aged visibly. Aime'e, her dark, wind-swept hair falling across her face, seems as young and glamorous as ever.

It will be difficult for Lelouch's new film to match the success of the original, which collected the Golden Palm award in Cannes and two Oscars for best foreign-language film and best scenario in 1966. French critics have given the sequel mixed reviews.

It does, however, provide a useful point of reference to examine the changes that have come over France, the French cinema and directors like Lelouch in the past two decades.

Lelouch says he himself is happier and more fulfilled than he was 20 years ago. Youthful-looking at 48, he worries less about the future and derives more enjoyment from the present.

Although his newer films are technically more polished, the simplicity and innocence that characterized the new wave of French filmmaking in the '60s has been lost.

France, the country that invented the cinema, is still the largest producer of films in Western Europe. But the number of moviegoers is declining because of competition from home video; last year it dropped by more than 8 percent. And U.S. movies like "Rambo" and "Out of Africa" seem set to overtake home-grown French products at the box office.

"A Man and a Woman" cost about $100,000 to make, a relatively modest sum even in 1966. The budget for this year's sequel was $5 million. The plot of "Twenty Years Later" is infinitely more complicated than the original -- it is difficult at times to follow.

A script girl in the original, Aime'e has by now become a film producer. She has the idea of making a movie about her unfulfilled love story with Trintignant, who is now a rally driver.

After 20 years, the former lovers meet to discuss the project. The result is a film about a film with two other films for subplots. Cameras seem to be everywhere.

According to Lelouch, the idea of making the sequel originated as a joke back in 1966, when "A Man and a Woman" was first screened in Cannes. It developed into a serious project only a couple of years ago after a discussion with Aime'e.

He describes "Twenty Years Later" as a movie about the effects of time.

The most emotional scene, of course, is the reencounter between Aime'e and Trintignant after 20 years.

To make it as spontaneous as possible, Lelouch did not let his actors study their lines beforehand. The dialogue was whispered to them on the set while the scene was being shot from several camera positions.

"What I am proudest of are the miraculous moments that are impossible to shoot again," said Lelouch, one of the rare directors who act as their own cinematographers.

Parts of "A Man and a Woman" resurface in the new film. Journeys to and from Paris have been recreated, 20 years on, as have the scenes on Deauville beach at dusk.

The film ends with the man and the woman happy that they have found each other again, hand in hand at the end of the pier.

What happens to them next (the real-life parallels are not encouraging in view of the checkered marital past of both Trintignant and Aime'e) will be the theme of a new movie that Lelouch says he will make in 2006.

"We have promised ourselves that we will do it, even if we have to shoot the film in an old people's home," Lelouch said.