Polanski had told Variety he had been "seduced" by Harris's writing
Oscar-winning director Roman Polanski has pulled out of a screen adaptation of Robert Harris's best-selling novel Pompeii, reports say.
"I put a lot of work and energy into the development of Pompeii, so it is not without regret I have to decline my further involvement," he said.
Filming of the $130m (£64m) movie was to have begun in Italy this summer.
According to Screen Daily, however, the 74-year-old film-maker was unable to commit to a postponed shooting date.
"In order to ensure that a film of this calibre and scale is produced in the manner required, the producers have pushed back the film to a time that will accommodate the production needs," said Patrick Wachsberger of financiers Summit International.
"While we are saddened that Roman will not be available to direct the film, we know we will work with the renowned film-maker and our friend in the near future."
Robert Harris's book tells the story of a young engineer who attempts to repair the Roman Empire's greatest aqueduct prior to the eruption of Mount Vesuvius in AD79.
Polanski had said the big-budget film would be "very dependent on visual effects".
The Paris-born director's films include Rosemary's Baby, Chinatown and The Pianist, for which he won a best director Oscar in 2002.