Wed Jun 13, 2007 8:28PM EDT - By Sue Zeidler

LOS ANGELES (Reuters) - From cartoon Avatars in the online world "Second Life" to the characters in video games, U.S. adults are embracing animation, say filmmakers, who see the form growing up and away from Hollywood's family-friendly cartoon staples.

Anime, the popular Japanese animation film format that is often used to tell complex dark stories, has also been inspiring filmmakers who think it could catch on with older audiences.

"We used to hear that animation for adults wouldn't work, but now all our competitors are doing the same," said Mike Lazzo, senior vice president of Cartoon Network's Adult Swim, the evening lineup of animated shows aimed at 18-to-34-year-olds, like "Robot Chicken" and "Aqua Teen Hunger Force."

The latter has spawned the film, "Aqua Teen Hunger Force Colon Movie Film for Theaters." Made for $1 million, it has already grossed nearly $6 million at theaters since its April opening and is being hailed as a cult hit.

"We think the same thing will happen with movies," Lazzo said. "Hollywood loves success and can't wait to pile on success. When Pixar started with 'Toy Story,' everyone began to put an animated feature in production, if not three." Cartoon Network is part of Time Warner Inc. TWX.N.