Variety.com said Portman left the movie due to a scheduling conflict with another project.

The actress was to have played Cathy, the tempestuous heroine in "Heights."

The trade paper said the film is still slated to start shooting in the fall, with British director John Maybury at the helm.

Portman is best known for her roles in "Beautiful Girls," three of the six "Star Wars" films, "Garden State," "V for Vendetta" and "The Other Boleyn Girl."