The effectiveness of that formula inevitably resurrects predictions that a marriage with a cable news organization is imperative for CBS and ABC. The obvious partner is CNN, and both those networks have been in courtships with it before. To date, the cultural challenges have been insurmountable. CNN, which says last year was its most profitable since its founding in 1980, would seem to have little incentive to rush to the aid of a network. And neither network wants to cede editorial control to CNN.

Image The producer Rick Kaplan in a CBS control room. The network's news division trimmed about 70 jobs this year. Credit... Christian Hansen for The New York Times

“If it were easy or obvious, it would have happened by now,” Mr. Heyward said.

But a longtime network news executive, who asked not to be identified because of connections to previous private negotiations involving CNN, said that ABC or CBS was likely to enter into an alliance with a partner like CNN “within the next few years.”

Even Mr. Westin, who said he did not see how a match with CNN “makes sense for us,” conceded: “In general, in business, when there is real decline, consolidation inevitably happens.”

Already, outlines of consolidation are discernible. Several CNN stars contribute to “60 Minutes” on CBS. And CBS executives, mindful that Katie Couric’s contract expires in a little over a year, have talked to Anderson Cooper of CNN about an anchor job, according to two TV veterans informed of the meeting.

In recent months, a handful of ABC News reporters has appeared on the business channel Bloomberg, and the two organizations have tried to jointly hire at least one person, according to two staff members who asked not to be named because they were not authorized by their employers to speak. Those two, and two others, labeled the sharing by ABC and Bloomberg — what one person called flirting — a possible prelude to a broader news-gathering pact.

A Bloomberg spokeswoman said that the company was a client of ABC’s affiliate service and declined to comment on any talks about a broader relationship between the organizations. An ABC spokesman said the current level of cooperation with Bloomberg was “hardly unusual.”