LOS ANGELES (Reuters) - After just six days of release in North America, the new Batman sequel "The Dark Knight" has grossed more domestically than its predecessor did in its entire run, distributor Warner Bros. Pictures said on Wednesday.

The Time Warner Inc-owned studio projected the film would sell about $17 million worth of tickets on Wednesday, taking its U.S.-Canadian total to about $221 million. It tallied $158.4 million of that sum during its first three days, setting a new opening-weekend record.

In surpassing $200 million on Tuesday, "The Dark Knight" took five days, breaking the record set in 2006 by "Pirates of the Caribbean: Dead Man's Chest," which took eight days to reach that mark.

By contrast, 2005's "Batman Begins," the first entry in the revived franchise, finished its four-month run with $205.3 million, according to tracking firm Box Office Mojo.

Both films were directed by English filmmaker Christopher Nolan, and star Welsh actor Christian Bale as Batman. Interest in the sequel was stoked by Heath Ledger's edgy turn as the villainous Joker. It represented the Australian actor's last completed role before he died of an accidental overdose of prescription pills in January.

Warner Bros. distribution president Dan Fellman predicted Thursday sales of about $16 million. And industry observers say that even if "Dark Knight" were to lose a respectable two-thirds of its business in its second weekend, it will have banked close to $350 million after its first 10 days. At that stage, it will be within striking distance of the worldwide haul of $372 million for "Batman Begins."

"The Dark Knight" will enter the top-10 for all domestic releases once it surpasses the $373.6 million tally for 2004's "Spider-Man 2." The studio is conservatively estimating domestic sales will eventually exceed $400 million, which would make "Dark Knight" the first film to break that mark since the 2006 "Pirates of the Caribbean" film.

Even with the Ledger-related buzz and overwhelming critical acclaim, Warner Bros. evidently took no chances on getting the word out, according to ratings firm Nielsen Co. It said on Wednesday that the studio ran nearly twice as many television commercials for "Dark Knight" (2,401) than it did for "Batman Begins" (1,287). The nine-week tracking period stopped 12 days before the launch of both films, Nielsen said.

(Reporting by Dean Goodman; Editing by Steve Gorman)