Tilda Swinton wins best supporting actress Oscar

Best supporting actress nominee Tilda Swinton from the film ''Michael Clayton,'' arrives at the 80th annual Academy Awards, the Oscars, in Hollywood February 24, 2008.

LOS ANGELES (Reuters) - Briton Tilda Swinton won the best supporting actress Oscar on Sunday for her performance as a ruthless corporate attorney in the legal thriller "Michael Clayton."

The 47-year-old star, who was born in London and attended West Heath Girls' School along with a young Princess Diana, has forged a successful career by tackling unconventional roles.

Swinton's big film break came in 1992, when she took the gender-bending title role of a nobleman in the art-house hit "Orlando." She achieved Hollywood stardom when she appeared alongside Leonardo DiCaprio in "The Beach" (2000) and in the critically acclaimed independent film, "The Deep End" in 2001.

Other film roles include "Adaptation" and "The Chronicles of Narnia: The Lion, the Witch and the Wardrobe," which featured her as the White Witch.

Her turn as a soulless lawyer in "Michael Clayton" also earned her a Golden Globe nomination this year for best supporting actress.

In the supporting actress category, she won against Ruby Dee ("American Gangster"), Saoirse Ronan ("Atonement"), Amy Ryan ("Gone Baby Gone") and Cate Blanchett ("I'm Not There").

(Reporting by Sue Zeidler, editing by Peter Henderson)