Jimmy Fallon to host NBC's 'Late Night'

Jimmy Fallon will officially be given the keys to NBC's "Late Night" franchise following Conan O'Brien's exit.

A person close to the negotiations who spoke on condition of anonymity because the announcement hadn't been made confirmed the widely rumored change Sunday and said a news conference was planned for Monday.

All that's left is an official date for NBC's transition: O'Brien moving out West to take over for Jay Leno on the "Tonight" show and Fallon following in the next time slot.

Fallon was a "Saturday Night Live" cast member before leaving for a movie career in 2004. He has had mixed success, with his most notable role as a childlike Boston Red Sox fan and Drew Barrymore's paramour in "Fever Pitch."

He signed a deal with NBC in 2007 that was widely seen as a way to keep him in the fold until the time came for Monday's announcement.

It would be hard for him to have a rockier transition than O'Brien had when he took over from David Letterman in the mid-1990s. O'Brien was a writer with a quick sense of humor but a mystery to the television audience, and he was savaged in early reviews. NBC nearly fired him but persevered, and O'Brien grew into the role.