Jay Leno, the long-running host, who has helmed the show since taking over from Johnny Carson in 1992, will be departing from his job in 2014 when his contract expires, leaving 'Late Night' presenter Jimmy Fallon to take over.
According to The New York Times newspaper, the NBC programme will also move back to its original home of New York once the transition takes place, where it was founded with Steve Allen in 1954 before being moved to Burbank, California, in 1972 under the reign of Carson.
There was no mention of the switch during the programme on Wednesday night, but Leno - who turns 63 next month - did criticise the network for their low ratings.
A senior executive taking part in the negotiations commented: "There is no way on earth that this is not going to happen."
Fallon's current role is in NBC's 30 Rockefeller Center studios and a spokeswoman revealed the network are building a new state-of-the-art studio in the same building when he takes control of 'The Tonight Show'.
NBC are reportedly keen to steer clear of any circumstances resembling previous transitions, which have cost the company their reputation.
One example is their attempt to replace Leno with Conan O'Brien three years ago, previous described as a "circus-like atmosphere" of musical chairs which saw the pair swap shifts.
Because of the lack of consistency, Leno was reinstated as host only seven months later.