The Hollywood Reporter said Friday the "Studio 60 on the Sunset Strip" actress will play the ex-wife of Cusack's character in "2012," which is focused on a global cataclysm that threatens humanity.
The movie's script was written by Emmerich and Harald Kloser. Mark Gordon and Larry Franco will serve as producers.
The disaster flick from the "Day After Tomorrow" director is to begin shooting in July and has a tentative release date of July 10, 2009.
The Reporter said Peet also is to appear in the upcoming "X-Files" movie sequel and an untitled comedy from director Nicole Holofcener.