Emma Watson arrives at a screening for new film The Perks Of Being A Wallflower at the Mayfair Hotel in London. File picture: Ian West/PA Wire

Harry Potter actress Emma Watson said she was nervous when taking her first major part since her starring role in the fantasy films.

The 22-year-old, best known for playing bookish wizard Hermione Granger will appear in The Perks Of Being A Wallflower, a drama based on Stephen Chbosky’s novel.

Wearing a black peplum dress and wide-legged trousers by Dior Couture, she said at a gala screening at London’s Mayfair hotel last night: “It was challenging. I was very nervous.

“Having played someone who was so restrained and very English to playing this free-spirited American girl, which was at the other end of the spectrum for me, it took a while to break down a lot of the barriers I didn’t even realise I had put up for myself.

“So when I did, it felt very liberating. I’m very proud of the film.”

Watson revealed she would be open to returning to the world of Harry Potter.

Author JK Rowling has teased that there could be more from the wizarding series after revealing she has left “the door ajar” for more books in the future.

“Of course. I’m open to anything,” said the actress.

Watson also said she can’t wait to read Rowling’s first adult novel, The Casual Vacancy, which hits the shelves today.

“Yes, absolutely. I haven’t seen it yet,” she said.

Logan Lerman and Ezra Miller also star in The Perks Of Being A Wallflower, which opens in cinemas next Wednesday.