Nina Foch, a veteran actress from Hollywood's film noir era of the 1940s who became a widely respected acting coach and teacher of directors, died Friday at the Ronald Reagan UCLA Medical Center. She was 84.

She died of complications from long-term myelodysplasia, a blood disorder, according to her son, Dr. Dirk De Brito.

Foch became ill Thursday while teaching "Directing the Actor," a popular course at USC's School of Cinematic Arts, where she taught for 40 years. She also offered the class for years at the American Film Institute. Her students have included accomplished directors, including Randal Kleiser, Amy Heckerling, Ed Zwick and Marshall Herskovitz.

"She was one of those few teachers who was truly life-changing," said Herskovitz, who with Zwick created and produced the critically acclaimed television shows "thirtysomething," "My So-Called Life" and "Once and Again."

"She had a point of view that was so profound and so provocative that it forced you to really reassess not just your thoughts about filmmaking but your whole approach to life and relationships," he said.

Herskovitz, who met Zwick in Foch's class at AFI in the 1970s, said her philosophy was difficult to boil down because it stemmed from her insights into how people behave and think and what they believe. "She had a wonderful phrase that used to torment us -- "idiosyncratic contrapuntal juxtaposition," he recalled Friday. "What it meant was what happens in life is often the opposite of what you think would happen, so the way you play a scene is often the opposite of the way you would think. . . . I'm not exaggerating when I say that what she taught us comes up literally weekly in our careers. She so influenced us in our way of looking at material, directing, even writing."

Foch began her career as an actress whose most memorable work was in the B-movie classic "My Name Is Julia Ross" (1945), directed by Joseph H. Lewis. Foch played a young woman who takes a job as secretary for a wealthy family and becomes ensnared in a plot to cover up a murder.

Her standout acting inspired a recent UCLA Film & Television Archive series celebrating Columbia's "noir girls" of the 1940s. In addition to "Julia Ross," the series featured films such as Fritz Lang's "Human Desire" and Rudolph Mate's "The Dark Past," which starred Foch opposite William Holden and Lee J. Cobb.

"She's really the reason we did these films," Andrea Alsberg, who curated the UCLA series, told The Times in October. "Nina is this tall, cool drink of water. She's not a dame, like Gloria Grahame. She's got class. 'Julia Ross' is a great, Hitchcockian thriller. And it's Nina that brings it alive. It's only 65 minutes, but you want to look at her the whole time."

Foch was born Nina Consuelo Maud Fock on April 20, 1924, in Leyden, Netherlands. Her father was the renowned Dutch composer-conductor Dirk Fock; her mother was actress Consuelo Flowerton. They divorced when Foch was a toddler.

She later moved to New York with her mother and enrolled at the American Academy of Dramatic Arts. She also studied Method acting with Lee Strasberg and Stella Adler. She changed her name to Foch when her movie career began in 1941 at Warner Bros. She worked under contract at several major studios, including Columbia, MGM, Universal, 20th Century Fox and United Artists.

Her film credits include "A Song to Remember" (1945), "An American in Paris" (1951), "Scaramouche" (1952) and "The Ten Commandments" (1956). She earned an Oscar nomination for best supporting actress in "Executive Suite" (1954).

Foch appeared on Broadway, including the 1947 hit "John Loves Mary." She briefly tried directing, serving as assistant director to George Stevens on "The Diary of Anne Frank" (1959), but turned to television acting when it became clear to her that the time was not ripe for a female director.

Her lengthy television credits include "Prescription: Murder" (1968), which launched the popular "Columbo" detective series starring Peter Falk, the miniseries "War and Remembrance" (1988) and episodes of "Gunsmoke," "Bonanza," "The Mod Squad," "Dharma & Greg" and "NCIS." She earned an Emmy nomination for best supporting actress in a drama series in 1980 for her work on an episode of "Lou Grant."

Foch taught two classes a week at USC, where her course was a requirement in a master of fine arts program.

"Believe it or not, teaching is the most rewarding thing I do," Foch told United Press International in 1994. "It has been the most successful thing I've done in my life."

Thrice married and divorced, she is survived by three grandchildren, in addition to her son. Services were pending.

Woo is a Times staff writer.

elaine.woo@latimes.com