Keira Knightley to star in the movie Diana

Keira Knightley, English film actress, is set to play Princess Diana in a new movie called Diana based on the life of the late princess of Wales.

Knightley is at the top of the list of a number of actresses lined up to play Diana. And producers at film company Pathe are keen to cast Knightley, 25, as Diana along with The Queen actress Helen Mirren, 65, as her mother and have started work on the project.

The film is expected to release in 2011, when Diana would have turned 50. The year also marks 30 years of Diana's wedding to Prince Charles. It is also reported to be the year when Prince William finally marries long-term girlfriend Kate Middleton.

"The project is in the early stages, but Pathe has chosen 2011 quite deliberately." the Daily Mail quoted a source as saying.

"It will be in the same vein as their movie The Queen and will detail the ups and downs of Diana's marriage and the early lives of the princes," the source added.