Sir Ian McKellen has confirmed 'The Hobbit' will start filming in July.

The veteran actor - who will reprise his role as Gandalf in the 'Lord Of The Rings' prequel, which is being split into two parts - says the script is "crammed with old friends" from the previous trilogy, though casting is not yet complete.

He wrote on his official website: "The Hobbit's two films start shooting in New Zealand in July. Filming will take over a year. Casting in Los Angeles, New York City and London has started. The script too proceeds. The first draft is crammed with old and new friends, again on a quest in Middle Earth."

The 70-year-old star also revealed that the movies' director, Guillermo Del Toro, is so dedicated to the project he has moved closer to producer Peter Jackson and the main set in New Zealand.

He added: "The director Guillermo del Toro is now living in Wellington, close to the Jacksons' and the studio in Miramar."

While filming on the movies is scheduled to behind within months, Ian, Andy Serkis, who reprises his role as Gollum, and Hugo Weaving, who will play Elrond, are the only confirmed cast members.

It is heavily rumoured that a British actor will play lead character Bilbo Baggins.