Blanchett to return as elf queen, while there are also parts in The Hobbit for Sylvester McCoy, Ken Stott and Ryan Gage

Her character does not even appear in JRR Tolkien's fantasy tale, but that has not stopped Peter Jackson from casting Cate Blanchett as Galadriel in his forthcoming two-part big-screen adaptation of The Hobbit.

Blanchett played the elf, a kindly but powerful leader of her people, in Jackson's Lord of the Rings trilogy between 2001 and 2003. Her appointment suggests the film-maker may be preparing to tinker with Tolkien's text once again to ensure The Hobbit maintains consanguinity with its predecessors.

The Kiwi director and his writing team beefed up a number of female roles in Lord of the Rings, including that of elf Arwen, who is hardly mentioned in the novels. Given that almost all The Hobbit's main participants are male, he may have his work cut out this time around.

Jackson's team confirmed that former Doctor Who Sylvester McCoy would play wizard Radagast the Brown, a colleague of Gandalf the Grey, in The Hobbit. Sir Ian McKellen is likely to play Gandalf again, but producers have not yet confirmed his involvement. It was also announced yesterday that Ken Stott (Charlie Wilson's War) would play dwarf Balin, while Swedish actor Mikael Persbrandt takes on the role of shape-shifting bear-man Beorn. British actor Ryan Gage will play hobbit Drogo Baggins and New Zealand actors Jed Brophy and William Kircher were announced as the men to bring dwarves Nori and Bifur to the screen.

Jackson is planning to begin shooting The Hobbit in New Zealand in February, so it is likely there will be further casting announcements before the end of the year. The project has been beset by delays and a highly publicised industrial dispute which, at one point, saw Jackson threatening to up sticks and move the shoot to a different country. The films were originally going to be directed by Guillermo del Toro, but he quit in May citing delays. That allowed Jackson, who had been expected to take a writing and producing role, to return to the top job.