If Sunday's estimates hold when final numbers are released Monday, "Fahrenheit 9/11" would set a record in a single weekend as the top-grossing documentary ever outside of concert films and movies made for huge-screen IMAX theaters.

Adding the film's haul at two New York City theaters where it opened two days earlier than the rest of the country, boosted "Fahrenheit 9/11" to .96 million.

"Bowling for Columbine," Moore's 2002 Academy Award-winning documentary, previously held the documentary record with .6 million.

"Fahrenheit 9/11," Moore's assault on US President Bush's actions after the 2001 terrorist attacks, won the top honor at last month's Cannes Film Festival and has attracted attention from both sides in the US presidential campaign.

The movie has been embraced by left-wing groups, which mobilized members to see it during the opening weekend. Conservative groups sought to discourage theaters from showing it and asked the Federal Election Commission to examine its ads for potential violations of campaign-finance law regulating when commercials may feature a presidential candidate.

"I want to thank all the right-wing organizations out there who tried to stop the film, either from their harassment campaign that didn't work on the theater owners, or going to the FEC to get our ads removed from television, to all the things that have been said on television," Moore said. "It's only encouraged more people to go and see it."

"Fahrenheit 9/11" opened in 868 theaters, a wide release for a documentary but narrow compared to big Hollywood flicks.

Distributors Lions Gate and IFC Films plan to put "Fahrenheit 9/11" into a couple of hundred more theaters this Wednesday, when competition heats up with the release of "Spider-Man 2," summer's most-anticipated movie.

(Agencies)