Oscar winner Gwyneth Paltrow has joined the cast of "Iron Man," the Jon Favreau-directed film that is being financed by Marvel Studios and released by Paramount Pictures in May 2008.

Paltrow joins Robert Downey Jr. -- who plays armor-clad superhero Iron Man and his alter ego, billionaire industrialist Tony Stark -- and Terrence Howard, who will play Stark's best friend Rhodey.

Paltrow will play Stark's personal assistant Virginia "Pepper" Potts, one of the few people in Stark's life who can go toe-to-toe with him and who occasionally serves as his conscience. The pair also share a secret attraction to each other.

Production is scheduled to begin in March in Los Angeles.