Tom Rosenstiel was right that network news is different from cable in that it presents "carefully written and edited stor[ies]" instead of live, largely studio-based coverage ["The End of 'Network News,' " op-ed, Sept. 12]. He was also right that cable and other alternatives have drawn away some of the networks' audience.

But he erred in saying that the reason for the shift is because the networks no longer broadcast long segments of political conventions.

Indeed, Mr. Rosenstiel implicitly contradicted his own thesis: If well-produced and edited pieces distinguish network news, what does that have to do with the live broadcast of the political infomercials that the conventions have become?

Mr. Rosenstiel also overlooked the reach and the seriousness of network news today. While the audience for any given network news program generally has gone down in the past 20 years, the hours of news provided have gone up dramatically and so, accordingly, has the networks' overall reach. For example, ABC News today reaches more than 200 million Americans every month -- by television, radio, computer and wireless devices.

According to every objective measurement -- the number of prime-time documentaries aired, investment in enterprise journalism, dollars spent on domestic and international news gathering, number of employees, and overall resources -- our commitment to serious journalism is stronger today than it was in the days when it was viewed as a loss leader designed to curry favor with regulators in Washington.

DAVID WESTIN

President

ABC News

New York