"I don't want anyone else to play Gandalf, I enjoy going to New Zealand and I have fun working on these films, so it wasn't a difficult decision to make."
The first part of Peter Jackson's The Hobbit: An Unexpected Journey, will be released in December and is one of the most hotly anticipated movies of the year.
It stars Martin Freeman as Bilbo Baggins, Benedict Cumberbatch as Smaug the dragon, Richard Armitage as Thorin Oakenshield and Cate Blanchett as Queen Galadriel.
The second and third instalments are expected to screen by 2014.
Actors from other mystical films also made the Sunday Times Rich List, including wizard actor Daniel Radcliffe whose leading role in the eight Harry Potter films puts his estimated fortune at £54 million (NZ$105 million).