Hollywood director Guillermo del Toro said Monday that production delays have forced him to quit the planned film version of J.R.R. Tolkien's "The Hobbit," a two-part prequel to New Zealand filmmaker Peter Jackson's blockbuster trilogy "Lord of the Rings."

"In light of ongoing delays in the setting of a start date for filming The Hobbit, I am faced with the hardest decision of my life," del Toro told a "Lord of the Rings" fan website.

"After nearly two years of living, breathing and designing a world as rich as Tolkien's Middle Earth, I must, with great regret, take leave from helming these wonderful pictures," he said, noting the film still hadn't been given the green light by MGM, the struggling Hollywood studio.