Batman blockbuster "The Dark Knight" has become the fastest film in history to pass 400 million dollars at the North American box-office, according to movie theater sales figures Tuesday.

Box-office tracker Exhibitor Relations said the critically acclaimed Warner Bros. hit passed the milestone on Monday after adding another 6.3 million dollars to its overall take on only its 18th day of release.

The film, a follow-up to 2005's "Batman Begins", has now earned 400,038,494 dollars, Exhibitor Relations said, making it the eighth highest grossing film of all time.

The film had already seized the record for best opening and second weekends -- 158.4 million dollars and 75.2 million dollars -- and became the fastest film to reach the 200 million and 300 million dollar marks.

DreamWorks' 2004 animated film "Shrek 2" had been the previous fastest film to reach 400 million dollars, but took more than twice as long -- 43 days.

"The Dark Knight," which stars Christian Bale as Batman and the late Heath Ledger in a widely acclaimed turn as the villainous Joker, is now on course to depose "Star Wars" as the second highest grossing film of all time.

George Lucas's "Star Wars" earned 461 million dollars after its original 1977 release and later re-releases.

Exhibitor Relations analyst Jeff Bock said however "The Dark Knight" is unlikely to threaten 1997's "Titanic" and its all-time US and Canadian take of more than 600 million dollars.

"I just don't see it passing 'Titanic'," Bock said. "'Titanic' was a phenomenon -- it actually increased from week to week, which is unheard of.

"'The Dark Knight is doing something extraordinary in terms of grosses but it is following the law of diminishing returns. It's still holding up very well but the take is getting smaller.'"