"Tonight Show" presenter Jay Leno, pictured in West Hollywood, California, on February 26, 2012
America's late-night TV hosts appear set for a new shake-up, with veteran "Tonight Show" presenter Jay Leno said to be hanging up his microphone after falling out with his NBC bosses.
In the latest reshuffle in the prized late-night slots, 62-year-old Leno is expected to hand over next year to hip pretender Jimmy Fallon, 38, who could move the iconic show from Los Angeles to New York.
If confirmed, the swap would be the second time Leno has left the "Tonight Show" in four years, after his botched 2009 replacement by Conan O'Brien triggered a ratings slump, leading to his return within months.
The show's move to New York could be good news for another younger late night host, Jimmy Kimmel, leaving the 45-year-old alone on the West Coast to book LA-based stars for his show.
Only David Letterman -- who at 65 recently overtook "Tonight Show" legend Johnny Carson as the most long-running late-night talk show host -- will remain unfazed by the looming changes on his CBS show.
The New York Times was the first to report this week that Leno is set to be replaced by Fallon, whose "Late Night With Jimmy Fallon" show is also on NBC, when Leno's contract runs out next year.
Although NBC has not yet signed a contract with Fallon, it is considered largely a formality, the newspaper reported, citing several executives as saying the move will likely happen before the fall of next year.
Leno's relations with NBC have been strained of late after the burly "Tonight Show" host made a series of gags in his opening monologues about the network's poor ratings, and his bosses.
Specifically, he triggered an angry email response from NBC executive Robert Greenblatt, responsible for the network's primetime scheduling -- but Leno has stood firm, continuing to crack jokes at NBC's expense.
"You know the whole legend of St Patrick, right?" he said, after Ireland's St Patrick's Day last weekend. "St Patrick drove all the snakes out of Ireland -- and then they came to the United States and became NBC executives.
"It's a fascinating story," he quipped.
Leno's show still leads late-night ratings. But NBC is understood to be keen to counter the perceived threat from Kimmel, after ABC moved his show in January to an earlier 11:35 pm slot, to compete head-to-head with "Tonight."
Fallon is seen as a better prospect for attracting younger viewers with his edgier, more Internet-savvy comedy, and skits like his recent "History of Rap" duets with Justin Timberlake.
NBC does not want to delay too long before making the switch, wary of giving Kimmel time to lock in younger viewers, who are crucial to late-night advertisers.
In any case, if "Tonight" moves to the East Coast, Kimmel will be left as the only late-night network show in LA, where his studio is just off Hollywood Boulevard in the heart of Tinseltown.
Industry journal The Hollywood Reporter said the "biggest smiles may well be on the faces of Scott Igoe and the music booking team at ABC's 'Jimmy Kimmel Live.'"
"Kimmel will be the only network option in Los Angeles in the 11:30 p.m. hour, giving the show extra clout when it comes to attracting star acts that have traditionally picked the higher-rated" Leno show.
It is not clear what Leno will do when and if he leaves "Tonight" again. When O'Brien replaced him in 2009, he stayed with NBC, hosting "The Jay Leno Show" at the earlier hour of 10:00 pm.
Ratings for both shows were poor, and the chastened network rapidly changed its mind, bringing the veteran back to his iconic perch nine months later, in March 2010.