LOS ANGELES – NBC's late-night woes have become the biggest drama on US television as comedians and TV executives trade increasingly bitter barbs in public.



With the struggling network still scrambling to sort out its failed prime-time experiment with host Jay Leno, Conan O'Brien and Jimmy Kimmel have played out their talk show wars with Leno all week in what media watchers called a public relations disaster from which NBC could be slow to recover.



Senior NBC sports executive Dick Ebersol entered the fray on Friday, blaming O'Brien for much of the fiasco and telling the New York Times the on-air jokes against Leno were "chicken-hearted and gutless."



"It is a PR nightmare, not just for NBC but for Leno and Conan," said Todd Gold, managing editor of Fancast.com.



"What is most surprising is seeing this happen on the network that carries their shows," Gold told Reuters.



Media reports suggested NBC was close to resolving the mess.



Hollywood insider website TheWrap reported late Friday that the network had agreed to pay O'Brien $30 million to exit "The Tonight Show." NBC told Reuters the report was "not true".



The Daily Beast said earlier O'Brien would leave and be free to take a job elsewhere, despite reported threats from NBC that it would prevent him from working on a rival channel.



NBC, which is at the bottom of the big four US TV networks in audience share, has made no official comment on the talks, which also reportedly put Leno back in his old job as host of the flagship "The Tonight Show."



The vitriol started even before NBC confirmed on Sunday that it would end in February the cost-cutting "The Jay Leno Show" in the 10 p.m. prime-time slot because of low ratings and a backlash from its local TV stations.



O'Brien bitter



Earlier hopes that NBC could swiftly move Leno to his old 11:35 p.m. time slot and push "The Tonight Show with Conan O'Brien" back to 12:05 a.m. disappeared when O'Brien released a bitter statement refusing to participate in what he called the destruction of "The Tonight Show."



Since then, O'Brien has placed a sales ad on popular web site Craigslist for a "barely used late-night talk show," and joked that young people should be inspired to believe they can "do anything you want in life -- unless Jay Leno wants to do it, too."



Jimmy Kimmel, late night host of ABC's "Jimmy Kimmel Live!" told Leno on his show on Thursday: "Listen Jay, Conan and I have children, all you have to take care of is cars. I mean, we have lives to lead here, you've got $800 million. For God's sake, leave our shows alone."



The drama has boosted audiences for both O'Brien's and Leno's shows, but not enough to beat the competition that caused the trouble in the first place.



Meanwhile late-night CBS rival David Letterman took a shot on Thursday, quipping; "NBC announced it was putting the NBC peacock (network symbol) on the endangered species list."



Media watchers question how quickly Leno, O'Brien or NBC can recover from the shouting match.



"How damaging is it? We won't know until after the winter Olympics and NBC puts their new schedule to the test. All of these things will play out and viewers will make their decision -- are they going back or not?," said Bill Carroll, a media analyst with Katz TV group.



Brian Steinberg, TV editor for Advertising Age, said the on-air scrapping was not good for NBC. More importantly, ad buyers are wondering "whether Leno will be able to come back right away if he goes to 11:30 p.m. Or has he lost some of his audiences to Letterman or the late night options out there?"