Emma Watson is about to sign a six-figure deal to become the latest ambassador for Lancome.

The campaign is to be shot by celebrated fashion photographer Mario Testino next month, and will feature Emma as the face of the French beauty brand in posters and TV advertising.

‘It’s so exciting, I can’t wait to start shooting,’

Emma, 20, said. ‘Although I don’t wear much make-up I’m a big fan of Lancome products, especially their mascara.’

The fresh-faced actress will be quite a change from Lancome’s previous thirtysomething ambassadors, who have included Juliette Binoche, Uma Thurman and Julia Roberts.

The deal comes as Emma prepares to bid farewell to the Harry Potter series, in which she has played Hermione since she was ten, with the final film out later this year.

The star – who cut her hair short to mark the end of life as Hermione – will fit her Lancome role around studies at Brown University in America.

Emma was being her usual stylish self on Friday night at a party at the Almada bar in London's Mayfair in honour of Colin Firth and The King's Speech, the runaway success of this year's awards season, accompanied by movie mogul Harvey Weinstein.