Citing its policy barring ads dealing with "public controversy," the NBC network said on Friday it rejected a TV commercial for a new film documenting the furor over the Dixie Chicks' criticism of President George W. Bush.

Ads for the documentary Shut Up & Sing also were rebuffed by the smaller CW network, though local affiliates of all five major broadcasters, including NBC and CW, ran promotional spots for the film in New York and Los Angeles, the two cities where it opened on Friday.

The ad features footage of lead singer Natalie Maines declaring during a London concert in March 2003 that the band was "ashamed" to come from the same state--Texas--as Bush.

The film's distributor, the Weinstein Co., seized on the rejection of its spots as evidence of political censorship by NBC and CW and said it was "exploring taking legal action."

The studio provided media outlets copies of "clearance" reports from NBC's standards and practices department bearing handwritten notations stating the ads were deemed unacceptable because "they are disparaging of President Bush."

Similar documents from the CW cited "concerns we do not have appropriate programming in which to schedule this spot."

"It's a sad commentary about the level of fear in our society that a movie about a group of courageous entertainers who were blacklisted for exercising their right of free speech is now itself being blacklisted by corporate America," studio co-owner Harvey Weinstein said in a statement.

A spokeswoman for Weinstein, renowned for aggressive marketing tactics as former co-chief executive of Miramax Films, dismissed suggestions by several industry sources that his attack on NBC and CW amounted to a publicity ploy.

"The idea that we're making an issue of this for the sake of publicity is nonsense," she said. "We're making an issue of this because we want the networks to run our ads."

NBC, a unit of General Electric Co., and CW, a joint venture of CBS Corp. and Time Warner Inc.'s Warner Bros. studio, denied they were engaging in political censorship.

NBC said it was merely following its "policy of not broadcasting ads that deal with issues of public controversy." A CW spokesman said the press release issued by the Weinstein Co. was "flat-out inaccurate, period."

"We asked them where they wanted to air (the spot) on the network, and then they said, 'We don't have plans for a buy.' That's really all I can tell you."

The studio said it is routine for movie distributors to seek advance network "clearance" for ads promoting limited-release films before deciding whether to proceed with a national advertising campaign.

A spokeswoman for the Dixie Chicks said the country pop trio were on tour in Canada and unavailable for comment.

But the liberal advocacy group People for the American Way weighed into controversy, saying NBC appeared to be trying to squelch political dissent less than two weeks before the mid-term congressional elections. "This is a film about censorship, and now it sounds as though it's being censored," the group's president, Ralph Neas, said.

CBS and Fox, a unit of News Corp. Ltd. said they had approved the ads for network broadcast, but ABC, owned by the Walt Disney Co. said it has not yet decided.

Shut Up & Sing, directed by Cecilia Peck and Oscar winner Barbara Kopple, offers a behind-the-scenes look at the backlash sparked by Maines' anti-Bush outburst in 2003.

Maines later said she was sorry for "disrespecting the office of the president" but fanned flames anew when she retracted her apology in a Time magazine interview this year, saying: "I don't feel he is owned any respect whatsoever."

Many country music radio stations reacted by refusing the play the Chicks' records, and some even boycotted ads for their current "Accidents & Accusations" tour, leading the band to cancel numerous dates in the South and Midwest.