Hollywood star Leonardo DiCaprio (L) and director Martin Scorsese speak at the Japan Premiere of their movie "The Departed" in Tokyo January 19, 2007. REUTERS/Toshiyuki Aizawa

LOS ANGELES - Martin Scorsese's crime thriller "The Departed" is almost certain to grab a slot in the Oscar race for best film, along with the musical "Dreamgirls" and the comedy "Little Miss Sunshine," when Academy Award nominations are announced on Tuesday.

Oscar pundits say those three films are likely to square off against "Babel," a saga of clashing cultures, and "The Queen," a portrait of the British royal family, in the competition for Hollywood's highest honors.

All five already have been nominated for best picture by two of Hollywood's most influential trade groups -- the Directors Guild of America and the Producers Guild of America -- whose picks usually predict Oscar sentiment.

"This year we've seen unprecedented agreement among the guild awards for five front-runners for best picture," said Tom O'Neil, awards columnist for the Web site TheEnvelope.com. "It's a fairly easy year to predict the nominations."

"Babel" and "Dreamgirls," the film adaptation of a Broadway hit loosely based on the Motown music group Diana Ross & the Supremes, gained momentum last week by winning Golden Globe awards for best film drama and best comedy or musical.

And "Little Miss Sunshine," a low-budget road comedy about an unlikely young beauty queen and her quirky family, got a boost as the surprise choice for best picture at the Producers Guild awards on Saturday night.

DARK HORSE CANDIDATES

But O'Neil said that any of the five presumed Oscar favorites could find themselves bumped off the list for best film by one of several dark horse candidates, including the comic sensation "Borat" and Clint Eastwood's Japanese-language war film "Letters from Iwo Jima."

That is because the Oscar ballot system makes it possible for a film to land one of the five best-picture nominations by garnering support from one-sixth plus one of the votes cast by the Academy of Motion Picture Arts and Sciences.

"The point is, all you need is a small, passionate core of support to get a nomination. You don't need the bulk of the academy," O'Neil told Reuters.

The mock documentary "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan" also is a wild card in the race for best actor. It remains to be seen whether its star, British comedian Sacha Baron Cohen, can gain Oscar recognition for his slapstick, often bawdy performance as a cluelessly offensive journalist from Central Asia.

Other big questions are whether Leonardo DiCaprio will land a best-actor bid for either "The Departed" or "Blood Diamond" -- Oscar rules bar him from competing for both -- and whether Brad Pitt will be nominated as best actor or best supporting actor in "Babel."

WILD CARDS

Other critically acclaimed wild cards that stand a chance of clinching a nod for best picture are "United 93," a drama set aboard one of the airliners seized by suicide hijackers on Sept. 11, and the Spanish-language film "Pan's Labyrinth," which mixes a dark fantasy with the horrors of war.

"Labyrinth" is a favorite for nomination as best foreign-language film, along with Pedro Almodovar's "Volver," starring Penelope Cruz.

The biggest commercial success in terms of the five most likely Oscar contenders for best film is "The Departed," which has grossed more than $121 million domestically and is still playing in theaters. Notwithstanding longshot "Borat," which has grossed $127 million, the others rank relatively low on the box-office scale.

In the contest for best director, Scorsese, 64, is a shoo-in to be nominated for "The Departed," a tale of double-dealing cops and gangsters. And he is favored to win, by virtue of an Oscar dynamic that O'Neil calls "the overdue director's syndrome."

The filmmaker behind such classics as "Taxi Driver" and "Goodfellas," Scorsese has never won an Academy Award despite five nominations as best director.

His most likely rivals include Bill Condon for "Dreamgirls," British filmmaker Stephen Frears for "The Queen," Mexican director Alejandro Gonzalez Inarritu for "Babel" and Eastwood for "Letters from Iwo Jima."

Two performers are seen as sure bets to vie for best actor -- Forest Whitaker for his role as Ugandan dictator Idi Amin in "The Last King of Scotland," and veteran Peter O'Toole for playing an aging actor who falls for a young woman in "Venus."

An Oscar triumph would be especially gratifying for O'Toole, who has been nominated as best actor seven times without winning.

The front-runners for an Oscar bid as best actress this year are Penelope Cruz for "Volver," Judi Dench for "Notes on a Scandal," Helen Mirren for "The Queen," Meryl Streep for "The Devil Wears Prada" and Kate Winslet for "Little Children."