ATLANTA — Viewers who grumble that the only news on TV is bad news soon will be able to choose some of the stories they want to see on Cable News Network.

CNN announced Thursday the first experiment in “interactive news” by a national network — a program similar to ones by smaller stations where viewers vote on whether to see “Godzilla” or “Planet of the Apes” as the late-night movie.

The experiment begins July 23 on CNN’s “Newsnight,” an hour-long newscast at midnight. The choices will involve secondary news or features.

Viewers will see a summary of headlines at the beginning of the show and, as anchors read the day’s top news, dial a 900 telephone number to vote on which of the stories they’d like to see. The stories that get the most votes, which cost 95 cents per call, will be shown.

CNN officials emphasize that viewers won’t be dictating news value but will tell the network what areas, outside of breaking news, most interest them.

“We’re not going to let viewers decide the editorial policy of CNN,” said spokesman John Bianchi. “A lot of stuff does not make it on the air that we do in fact cover. This is a way to get more of the stuff on the air that we might not have made the decision on initially.”

Bianchi said CNN, which had trouble filling all its newscasts when it was started by media mogul Ted Turner in 1980, doesn’t have enough time now to air all the stories it would like to. So viewers — in 54 million U.S. households and 90 countries — are being asked to let producers know their preferences.

“We can tell by the volume and quality of viewer phone calls and letters we receive each day that CNN has very informed viewers,” said CNN Senior Executive Bob Furnad. “This new interactive segment will allow those viewers to tell us in a relatively direct fashion the kinds of information they most want.”

At least one of CNN’s network competitors reacted with surprise to the announcement. Asked if the concept would spread to the Big Three networks, CBS spokesman Tom Goodman said, “It doesn’t sound like something we’d get involved in.”

The public relations departments at NBC and ABC offered no immediate response.

Interactive television, a concept of two-way communication between viewers and programmers with TV remote controls, emerged in the early 1980s.

Warner Amex Cable Communications Inc. developed the first interactive technology, called “Qube,” in Ohio in 1981.