LONDON: Keira Knightley has been tipped to star in a new version of 'My Fair Lady'.

The 'Pirates of the Caribbean' actress is reportedly in negotiations to play Eliza Doolittle in Emma Thompson's adaptation of the classic rags-to-riches tale.

Anne Hathaway and Scarlett Johansson are also being considered for the role, which was originally played by Audrey Hepburn.

An insider said: "Keira and Scarlett are the only two real contenders and Keira's the favourite. She's the most natural Eliza people have seen.

"She has worked on her singing voice for a year and will get better and better."

The film's director Danny Boyle - who won an Academy Award for 'Slumdog Millionaire' earlier this year - is also believed to want Keira to get the part.

The 24-year-old actress is said to be "scared" about taking on such an iconic role, but excited about the challenge it would present.

Filming is expected to start late next year.