Director Peter Jackson has reunited the team behind the Lord of the Rings movies for the first instalment of a new trilogy that Hollywood insiders estimate will cost up to $1 billion to make and market.

The long-awaited adaptation of J.R.R. Tolkien's fantasy novel, about Bilbo Baggins' adventure with 13 dwarves to recover treasure guarded by a dragon named Smaug, makes it debut in Wellington on Wednesday.

And there is much riding on its being a success.

For a start, even with the massive goodwill generated by Jackson's return to Middle Earth, The Hobbit: An Unexpected Journey is a financial gamble for Hollywood studios Warner Bros and MGM.

The trilogy will also have a multibillion-dollar impact in New Zealand, given how much The Lord of the Rings boosted tourism. From 1999 to 2004, spending by international visitors doubled to $6 billion a year.

But probably the biggest risk is for Jackson's revered status with millions of Lord of the Rings fans.

As George Lucas discovered when he returned to the Star Wars saga with The Phantom Menace, devoted fans are quickly disenchanted when a movie does not match a director's own high standards.

New Zealand director Jackson overcame countless setbacks while filming the Lord of the Rings trilogy. The movies went on to gross almost $3 billion worldwide and won 17 Oscars.

It is almost unthinkable The Hobbit could be so successful on every level, but Jackson is actually being even more technically and creatively adventurous this time round. He has shot the movie in 3D at 48 frames-a-second rather than the usual 24 to give audiences a visually richer experience.

The movie also expands on the novel by using Tolkien's notes for a planned revision.

Jackson told Fairfax Media that there would be no sense that he is trying to drag out the story to fill three movies when audiences see An Unexpected Journey.

''It's a much faster-paced film than the Lord of the Rings films were and yet we only get part of the way through the story, of course,'' he said.

English actor Martin Freeman plays Bilbo Baggins, with the returning cast including Ian McKellen as Gandalf, Cate Blanchett as Galadriel and Hugo Weaving as Elrond.

More than a month before An Unexpected Journey opens in Australia, there have been strong advance ticket sales. Samantha Philp, the national film promotions and partnership manager for Event Cinemas, said ticket sales were twice that of The Avengers and 15 per cent up on The Dark Knight Rises after 16 days. And while short of the final Twilight and Harry Potter movies, some Gold Class sessions have already sold out.

The strong ticket sales come despite the movie receiving some advanced attention that those behind it would rather it hadn't.

Members of the animal rights group PETA plan to protest at the premiere about the alleged deaths of more than two dozen horses and other animals during the shoot.

Jackson and the film's producers said they ''completely reject'' the claims, with a representative saying some animals died of natural causes. A studio spokesman blamed the controversy on animal wranglers who were dismissed during filming.