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LOS ANGELES - It is not easy living up to the exploits of an older brother like Oscar-winner and box-office draw Ben Affleck, but actor Casey Affleck could soon eclipse his famous sibling if Hollywood's stars align.

If that happens and, as some expect, the younger Affleck competes for Oscars in the coming months, he will have two movies and at least one person to thank - the director of the upcoming Gone Baby Gone, who also happens to be his brother.

"We had common language, a shorthand that enabled us to communicate specifically," Casey Affleck told Reuters about being directed by Ben, who is three years older.

"We could disagree comfortably and when we agreed, we would elevate the conversation quickly and build on what each other said."

Unlike Ben, who won an Oscar at age 25 for co-writing Good Will Hunting and went on to leading man roles, Casey Affleck, 32, is only now transitioning from being a character actor, mostly in films with large ensemble casts such as Ocean's Eleven, to a leading man.

The first film in this movement, The Assassination of Jesse James by the Coward Robert Ford, debuted in major cities last Friday and expands its release on October 5. It tests Affleck's ability to hold his own in a leading role opposite major star Brad Pitt.

USA Today critic Claudia Puig called Affleck's work "the real revelation of the film" as he plays the coward Robert Ford, who befriends outlaw James (Pitt) only to shoot him in the back.

AVOIDING PITT-FALLS

Affleck said he was initially intimidated working with Pitt and other top professionals such as five-time Oscar-nominated cinematographer Roger Deakins.

"They are all very talented, and I knew I was going to have to elevate my game to keep up ... Sometimes I felt like, 'I don't know how I'm going to do this and do it well,'" he said.

He said he overcame his intimidation by showing up prepared, staying focused and utilising an age-old actor's technique: reacting to his co-stars instead of overacting on his own.

But so far, Pitt has earned the acclaim from Jesse James, winning best actor award at this month's Venice film festival.

That leaves Gone Baby Gone, debuting on October 19, as the movie that could cause Casey Affleck to break from Hollywood's pack of young leading men and claim his own, big star.

Unlike art house film Jesse James, Gone Baby Gone will get a wide US release, meaning it likely will be seen by more people and have a chance at a greater box office.

Another advantage is that Gone Baby Gone centers on a modern-day private detective in Boston (Affleck) hired to find a kidnapped 4-year-old girl, making it more likely to appeal to mainstream audiences than Jesse James, which challenges moviegoers with its meditation on the power of celebrity.

Early screenings are winning fans. Veteran critic Emanuel Levy gave the film a "B," but wrote: "Perhaps more importantly, the film signals a breakthrough year for ... Casey, who gives his second strong performance this year."

Affleck said playing the young private eye felt familiar because the film was shot in his hometown and he was comfortable baring his soul with his big brother behind the camera.

"Doing movies can be a sort of bonding experience," he said, "but it pales in comparison to 32 years of brotherhood."

- REUTERS