Brittany Murphy cast in 'Expendables'

David Zayas also joins Sylvester Stallone's action film

Brittany Murphy and David Zayas have joined the all-star cast of "The Expendables," Sylvester Stallone's actioner being produced by Nu Image/Millennium Films.

The pic -- which counts Stallone, Jason Statham, Mickey Rourke, Jet Li, Dolph Lundgren and Randy Couture among its cast -- follows a team of mercenaries who head to South America on a mission to overthrow a dictator.

Murphy will play Rourke's girlfriend, a singer. The part calls for her to perform a musical number.

Zayas will play the dictator.

Stallone wrote the screenplay and is directing the film, which began production this week in Brazil. The production also will lens in Louisiana.

Murphy, repped by Paradigm and Media Talent Group, most recently sang in "Happy Feet" and released an album titled "Faster Pussycat" on which she collaborated with Paul Oakenfold. She also is attached to "Sin City 2."

Zayas, repped by WMA and ATA Management, is best known for his role as Angel Batista on Showtime's "Dexter." His feature credits include "Michael Clayton," "The Savages" and "The Interpreter."