Nina Foch, a Dutch-born actress of stage and screen, who often played worldly women of cool, controlling instincts, died Dec. 5, 2008, at her home in Los Angeles. She was 84. She was best remembered as Milo Roberts, the sophisticated, wealthy sponsor of Gene Kelly's winsome painter in the M-G-M movie musical "An American in Paris." Her character's plan to guide Kelly's career and keep the handsome painter in the bargain is foiled by the allures of Leslie Caron. More calculating still was the cold-blooded Roman aristocrat Ms. Foch played in "Spartacus," a woman who decreed that gladiators fight to the death for her bemusement.

More sympathetic was her portrayal of Bithia, the pharaoh's daughter, in epic "The Ten Commandments," who adopts the baby Moses. She was nominated for an Oscar and won a National Board of Review Award for her performance as a lonely secretary in 1954's all-star drama "Executive Suite."

Ms. Foch (pronounced like "gosh") made her Broadway debut in the hit 1947 comedy John Loves Mary, in which she played the fiancée of a soldier. The Joshua Logan production ran for 423 performances. It was the biggest stage hit of her career. In 1949, she played Olivia in a Broadway production of Twelfth Night. One year later, she was Cordelia in a John Houseman-staged rendition of King Lear. In between, she played in a short-lived Christopher Fry one-act called A Phoenix Too Frequent. As a member of the American Shakespeare Festival at Stratford, she performed as Isabella in Measure for Measure and Katharine in The Taming of the Shrew.

Her most lasting impact on the stage, however, was as a teacher. She worked at the University of Southern California's film school for 40 years and with the American Film Institute's film studies center in the 1970s. "I've been busy in my career and all my life," Ms. Foch said. "But I think the biggest thing I've done in life is teach. Breaking down every scene, every line, every beat, and putting the piece together. That's my contribution."

She was born Nina Consuelo Maud Fock in Leyden, the Netherlands, on April 20, 1924. Her father was Dirk Fock, an conductor. Her mother was Consuelo Flowerton, an American-born actress. The couple divorced and, following a custody battle, Nina lived with her mother. Encouraged to pursue culture and the arts, she took piano and painting lessons, and graduated from the Lincoln School in Upper Manhattan, and attended the American Academy of Dramatic Arts.

Her three husbands include the pre-"Inside the Actors Studio" James Lipton (1954-59); Dennis Brite (1959-63); and Michael Dewell (1967-1993). All ended in divorce.

She is survived by a son and three grandchildren.