Sir Ian McKellen is to return to the role of Gandalf in JRR Tolkien's The Hobbit

The Lord of the Rings star told Empire magazine that it was not a part to turn down.

"Yes, it's true," he said, when asked if he was set to return. Obviously, it's not a part that you turn down, I loved playing Gandalf."

Guillermo del Toro has been confirmed as directing The Hobbit and its sequel.

The 43-year-old filmmaker will move to New Zealand for four years to make the films back-to-back with executive producer Peter Jackson.

Del Toro wrote and directed Pan's Labyrinth, which earned six Oscar nominations in 2006 and won three awards. He is also the director of the upcoming sequel Hellboy II: The Golden Army.

Asked if he was happy to be back in the robes again, Sir Ian said: "We talk occasionally and he's looking forward to coming out of retirement, yes.

"Guillermo will be getting around to starting the script in about six weeks when he's finished filming Hellboy II."

Sir Ian was also asked what would happen in the second film, which takes place before Fellowship of the Ring.

"Well I've read The Hobbit so I've got a good idea of what the story would be.

"But as to how it's going to work over two films and what going to happen on screen, well Guillermo has not got down to working out the major details yet - I can tell you it's going to be amazing though."