Filming of the widely-anticipated "Hobbit" movies will be delayed because director Peter Jackson is recovering from surgery for a perforated ulcer, a spokeswoman said on Thursday.

Jackson, 49, who directed the hit "Lord of the Rings" film trilogy in his native New Zealand, was admitted to a hospital in Wellington on Wednesday evening with acute stomach pains.

"Sir Peter is currently resting comfortably and his doctors expect him to make a full recovery," spokeswoman Melissa Booth said in a statement.

"The surgery is not expected to impact on his directing commitment to the Hobbit beyond a slight delay to the start of filming."

Filming of the two movies of "The Hobbit," based on the J.R.R. Tolkien fantasy novel, had been expected to start around the middle of February.

The first movie will be released in December 2012 and the second is expected a year later.

The movies have been beset by a succession of problems, most notably the threat last year by Time Warner Inc unit Warner Bros. to move production overseas because of fears unions would impose a boycott to back demands for a collective contract.

The move could have cost New Zealand an estimated $1.5 billion and threatened the country's fledgling film industry.

In response, the government last year changed labor laws to keep the estimated $500 million production and increased tax breaks for Warner Bros.

"The Hobbit" is based on the adventures of Bilbo Baggins, a hobbit who lives in the land of Middle-earth and goes on a quest to find treasure guarded by a dragon.

The book, first published in 1937, is the precursor to the "Lord of the Rings" trilogy, which also takes place in Middle-earth.

The cast for the movies includes Oscar winner Cate Blanchett, Ian McKellen, Orlando Bloom, Ken Stott and Martin Freeman.