`BYE BYE' STORY, HELLO ATMOSPHERE : THE FACTS.

Byline: Stephen Holden The New York Times

Every so often, Karim Dridi's intoxicatingly sensuous film ``Bye Bye'' pauses long enough for the camera to drink in the voluptuous, fetid atmosphere of the Mediterranean port city of Marseilles.

In the director's favorite shot, the movie's main character, Ismael (Sami Bouajila), visits the harbor to observe the steamships slipping silently in and out of port through a smoggy sunset. Such moments crystallize the feeling of wanderlust that permeates the film, lending it an aching romantic tug.

``Bye Bye'' isn't the French director's first infatuated portrait of a teeming city. His 1994 film, ``Pigalle,'' suggested a tourist exhibition of Paris' red-light district organized by Jean Genet.

The new film is a richer, more complex urban panorama that contemplates the racial and generational conflicts among the city's North African and French populations through the eyes of the 25-year-old Ismael and his 14-year-old younger brother, Mouloud (Ouassini Embarek).

The story begins in Paris with an enigmatic scene that flashbacks later reveal to be a family tragedy for which Ismael was responsible.

Fleeing to Marseilles, Ismael and Mouloud are welcomed into the crowded tenement home of their uncle (Benhaissa Ahourari) and aunt (Jamila Darwich-Farah), who, like the boys' parents, are immigrants from North Africa. Since the tragedy, Ismael's parents have moved from Paris back to their native Tunisia, and Ismael has been instructed to send Mouloud home to them.

Among the movie's several interlocking stories, the most sharply drawn follows Mouloud's descent into a world of drugs and crime under the aegis of his swaggering teen-age cousin, Rhida (Sofiane Mammeri).

In the film's most chilling scene, the naive Mouloud is given his first taste of heroin and allowed to handle a gun, which he is told is the key to one's manhood. To avoid being shipped back to his parents, Mouloud eventually hides out with a paranoid, trigger-happy crack dealer.

A good portion of the film follows Ismael around the city as he desperately tries to find his younger brother. The film is wonderful at atmosphere, and scene after scene evokes Marseilles's steamy multicultural bouillabaisse with a semidocumentary brio.

But ``Bye Bye'' isn't as adept at storytelling as it is at ambience. The tragedy that drives Ismael from Paris to Marseilles is too sketchily depicted and ultimately seems contrived. As Ismael, Bouajila is intriguingly smoldering but largely unreadable.

``Bye Bye'' is best appreciated as a series of pungent slices of urban life. If they don't add up to a whole loaf, they make for a tasty one.

The film: ``Bye Bye'' (not rated).

The stars: Sami Bouajila and Nozha Khouadra.

Behind the scenes: Written (in French with English subtitles) and directed by Karim Dridi.

Running time: One hour, 45 minutes.

Playing: Music Hall, Beverly Hills.

Our rating: Three stars