LOS ANGELES - Julia Roberts has signed on to produce and possibly star in "Happiness Sold Separately," a romantic feature based on the novel by Lolly Winston.

The story centers on a woman who withdraws from her husband into a world of heartbreak and anger after she discovers that he had an affair with his nutritionist at the gym. It tells the story of when people meet the wrong person at the wrong time and have to make it right.

Fox Searchlight is in early negotiations to distribute the project, which will be adapted and directed by Scott Coffey, an actor and longtime friend of Roberts.

"I've been looking for something to do with Julia for a really long time, and I finally found the project that was worthy of her," said Coffey. "I couldn't get Julia out of my head when I was reading Lolly's book. Elinor is such a strong, complicated woman, and bringing her to the screen required Julia's integrity, empathy, humor and legs."

Roberts is in production on "Charlie Wilson's War" opposite Tom Hanks, Phillip Seymour Hoffman and Amy Adams. She also is voicing the title character in the Paramount Pictures release "Charlotte's Web," which bows Friday.