Harry Potter star Emma Watson is the new face of Chanel

Emma Watson, who plays Hermione in the Harry Potter films, is to replace the Pirates of the Caribbean actor Keira Knightley as the face of Chanel's Coco Mademoiselle.

Eighteen-year-old Watson has reportedly signed a two-year contract with Chanel worth £3m.

She will replace Knightley when the latter's contract with Coco Mademoiselle runs out this summer. Knightley will remain with Chanel in a new role.

Watson has already developed a close association over recent months with the luxury fashion brand, which has dressed her for film premieres and parties.

Chanel is expected to officially announce the Coco Mademoiselle deal next month.

Warner Bros, which makes the Harry Potter films, is understood to have been involved in approving the deal.

As the face of Coco Mademoiselle, Watson follows in the footsteps of Kate Moss, who was signed up for the fragrance's launch in 2001, and 23-year-old Knightley, who took over in 2007.