New York ? The Dixie Chicks are again at the center of a controversy over the limits of opinionated talk.

A film company said Friday that NBC wouldn’t accept an advertisement for “Shut Up & Sing,” a movie about the fuss created by Dixie Chick Natalie Maines’ comment that she was ashamed President Bush was a fellow Texan. The network suggested the complaint may be a publicity stunt.

The movie premieres this weekend in New York and Los Angeles, and network affiliates in both those cities have run ads promoting it, according to the Weinstein Co., which is distributing the film.

The problem arose when the Weinstein Co. began conversations with networks about buying ads to be shown nationally, in anticipation of later wider release of the film.

The ad includes footage of the Iraq War, gives a brief background on Maines’ 2003 comment made onstage in London, and shows Maines dismissing as “dumb” a comment made by Bush about the Dixie Chicks.

CBS has agreed to air the ad, a spokeswoman for the Weinstein Co. said. ABC and Fox have not given an answer while the CW and NBC rejected it. The film distributors said NBC explained it was because the ad disparaged President Bush.

“We were very surprised, especially because this is a movie that deals with the whole issue,” said Gary Faber, head of marketing at Weinstein. He suggested that the statements made in the ad are not unlike the opinions offered by commentators on political talk shows.

But Alan Wurtzel, head of standards and practices at NBC, said it is network policy not to accept ads on issues of public controversy – like abortion or the war.

While the Weinstein Co. had shown NBC its ads, it had not inquired about buying commercial time, he said. Generally, when an ad is rejected, prospective advertisers return and work with the network on ways to make it acceptable – as was done with the Michael Moore film “Fahrenheit 9/11,” he said.

But NBC heard nothing more from makers of “Shut Up & Sing” until portions of what NBC executives thought were confidential business correspondence showed up in a news release, he said.

“There was no attempt to come back and have a conversation,” Wurtzel said. “There are times when some advertisers get more publicity for having their ad rejected.”

The CW said a Weinstein representative discussed the ad with a low-level network official who questioned whether the network had the right programming to fit the ad.

“It was the beginning of a dialogue at a low level and it didn’t get beyond that when they decided to go to the media about it,” network spokesman Paul McGuire said.

The CW would accept the ad if commercial time was bought, he said.