Ashley Olsen, Mary-Kate Olsen at 'Superheroes: Fashion and Fantasy' Costume Institute Gala at The Metropolitan Museum of Art - Departures, New York City, USA - 05.05.08

The 1970s and 1980s fashion icon will appear in campaigns and on the world's catwalks for the 22-year-old siblings' range.

Mary-Kate Olsen explains the sisters wanted Hutton, who now runs her own successful cosmetics company, from the start - and age was never an issue.

She says, "She's just a wise woman and she's a traveller and she's obviously a style icon."

Sister Ashley adds, "She's older and she's beautiful, and that is sexy to us."

Source: WENN