The parent companies declined to comment directly on the details of the cease-fire, which was orchestrated in part by Jeff Zucker, the chief executive of NBC Universal, and Gary Ginsberg, an executive vice president who oversees corporate affairs at the News Corporation.

Mr. Olbermann, who is on vacation, said by e-mail message, “I am party to no deal,” adding that he would not have been included in any conversations between G.E. and the News Corporation. Fox News said it would not comment.

Civility was not always the aim of Mr. Olbermann and Mr. O’Reilly, men who, in an industry of thin skins, are both famous for reacting to verbal pinpricks. Both host 8 p.m. programs on cable news in studios a few blocks apart in Midtown Manhattan.

The conservative-leaning Mr. O’Reilly has turned “The O’Reilly Factor” into a profit center for the News Corporation by blitzing his opponents and espousing his opinions unapologetically. He found his bête noire in the liberal-leaning Mr. Olbermann, the host of MSNBC’s “Countdown,” who saw in Mr. O’Reilly a regenerating target he nicknamed the “Bill-o the Clown.”

The 6-foot-4 Mr. Olbermann started sniping regularly at the also 6-foot-4 Mr. O’Reilly in late 2005, sometimes making him the subject of the “Countdown” segment, the “Worst Person in the World.” Mr. O’Reilly was also a stand-in for the perceived offenses of the top-rated Fox News.

By punching up at his higher-rated prey, Mr. Olbermann helped his own third-place cable news show. “Honestly, I should send him a check each week,” he remarked to a reporter three years ago. Fox noticed. Mr. Murdoch remarked to Esquire last year that “Keith Olbermann is trying to make a business out of destroying Bill O’Reilly.” Mr. O’Reilly refused to mention his critic by name on the “Factor,” deeming him a “vicious smear merchant,” but he regularly blamed Mr. Zucker for “ruining a once-great brand,” NBC.

In late 2007, Mr. O’Reilly had a young producer, Jesse Watters, ambush Mr. Immelt and ask about G.E.’s business in Iran, which is legal, and which includes sales of energy and medical technology. G.E. says it no longer does business in Iran.