Batman fans snap up tickets ahead of 'The Dark Knight' release

It doesn't open for another nine days, but midnight screenings of The Dark Knight have all but sold out in many US states.

The New York Times reported that tickets to the latest Batman movie were so sought after theatres were scheduling extra screenings at 6am on opening day - July 18 - for those who missed out on tickets to the midnight and 3am screenings.

Midnight screenings are no longer an unusual event when it comes to much-hyped films, but all-night sellouts in advance of a movie opening are almost unheard of.

The Dark Knight sees Christian Bale's Batman out to rid Gotham of organised crime for good. But Heath Ledger's character, the scarily deranged Joker, is determined to spread anarchy.

The New York Times said much of the interest in The Dark Knight was due to the presence in its cast of Ledger, who died earlier this year after filming wrapped.

His performance in the film has been described by Rolling Stone reviewer Peter Travers as "mad-crazy-blazing brilliant" and there are already rumours of an Oscar nomination for the late actor.

"In the public mind, opening weekends have been eventised," Thomas Tull, the chairman of Legendary Pictures and an executive producer of The Dark Knight, told The New York Times.

Indeed, movies - largely thanks to internet hype and online ticket sales - are now increasingly afforded the attention once reserved for rock concerts.

Three weeks out from The Dark Knight's launch, it had already sold eight times as many tickets throught movietickets.com as Spider-Man 3 had 21 days before its release.

In May, New York's entire supply of Ledger's Joker action figures sold out within minutes of going on sale.

* The Dark Knight opens in the US on July 18 and in New Zealand on July 24.