Hytner: Wants to direct the production himself

Mr Pullman was the first children's author to win the prestigious �30,000 Whitbread Prize when judges declared The Amber Spyglass, the final book in the trilogy, the best book of the year.

But a play version is unlikely to reach the stage until 2004, according to Mr Hytner, who will take over artistic control of the National from Trevor Nunn in April 2003.

Mr Hytner will direct the large-scale project himself, he told the Daily Telegraph newspaper.

"It's difficult and it's ambitious," he said. "You have to find a metaphorical way of telling those stories virtually on a bare stage but I am convinced it can be done."

The stories are set in strange, mythical worlds where every character is accompanied by a "daemon", an animal that is its guardian angel and epitomises its soul.

The Amber Spyglass has sold more than 1 million copies in the UK

Mr Hytner was "completely blown away" when he read the books, he told the newspaper.

The stories may have to be split up and staged on consecutive nights, as the Royal Shakespeare Company did with their 1970 adaptation of Charles Dickens's Nicholas Nickleby.

The young lead characters would be played by "young-looking 20-year-olds", he said, and the play would appeal to adults and children, like the books.

Mr Hytner has had a successful career as a stage director, and also directed the film version of The Madness of King George.

Mr Pullman's novel I Was A Rat was turned into a TV mini-series starring Tom Conti in 2001.