By Anthony Breznican
The Associated Press

Mystic River has gained Oscar momentum with a key Screen Actors Guild (SAG) nomination.

The film collected three nominations this week, including best ensemble cast - the guild's equivalent of a best picture category. The movie also was recognized for Tim Robbins' supporting turn as the survivor of childhood sexual abuse who finds himself the suspect of murder, and Sean Penn received a lead actor nomination for playing an ex-con.

The Station Agent matched Mystic River with three nominations, also picking up a best ensemble nod.

Patricia Clarkson received bids for both lead actress in The Station Agent for her portrayal of a lonesome artist and supporting actress for playing an angry cancer patient in Pieces of April.

Peter Dinklage, the diminutive star of The Station Agent, received a lead actor bid. He played a misanthropic dwarf who makes friends despite trying to isolate himself at an old train yard.

Johnny Depp, a surprise Golden Globe nominee last month for playing a wobbly swashbuckler in Pirates of the Caribbean: The Curse of the Black Pearl, picked up another bid for that role from SAG - a significant boost for his Oscar chances.

Other big-name stars - Tom Cruise from The Last Samurai, Russell Crowe from Master and Commander: The Far Side of the World and Nicole Kidman from Cold Mountain - were among those snubbed by the actors guild.

The 10th annual ceremony will take place Feb. 22 in Los Angeles. The guild's nominations are the last major awards announcement before the Academy Awards nominations Jan. 27.

SAG nominations are chosen by 4,200 randomly chosen members of the union. The guild's full membership of 98,000 is eligible to vote for winners.

Film nominees

Actor: Johnny Depp, Pirates of the Caribbean: The Curse of the Black Pearl; Peter Dinklage, The Station Agent; Ben Kingsley, House of Sand and Fog; Bill Murray, Lost in Translation; Sean Penn, Mystic River.

Actress: Patricia Clarkson, The Station Agent; Diane Keaton, Something's Gotta Give; Charlize Theron, Monster; Naomi Watts, 21 Grams; Evan Rachel Wood, thirteen.

Supporting actor: Alec Baldwin, The Cooler; Chris Cooper, Seabiscuit; Benicio Del Toro, 21 Grams; Tim Robbins, Mystic River; Ken Watanabe, The Last Samurai.

Supporting actress: Maria Bello, The Cooler; Keisha Castle-Hughes, Whale Rider; Patricia Clarkson, Pieces of April; Holly Hunter, thirteen; Renee Zellweger, Cold Mountain.

Cast performance: In America; The Lord of the Rings: The Return of the King; Mystic River; Seabiscuit; The Station Agent.