Updated

Conan O'Brien will take over the "Tonight" Show next June — and what happens to deposed host Jay Leno after that is anybody's guess.

Leno's last show will be a Friday, May 29, and O'Brien will start the following Monday, June 1, NBC executives told a Television Critics Association meeting Monday.

NBC is angling to keep Leno with the network, but the late-night king has indicated he's ready to jump ship. NBC competitors, including other networks and syndicators, are eager to help him make the leap.

Ben Silverman and Marc Graboff, NBC Entertainment co-chairmen, were asked about the specter of Leno being hired by ABC and overpowering O'Brien in the ratings.

"We really believe in the decisions we've made with our partners, including Jay" and are standing by them, Silverman replied.

Jimmy Fallon is poised to take over O'Brien's "Late Night" in March or April of 2009, after honing his approach in brief Internet shows, Silverman and Graboff said.

O'Brien will wrap his "Late Night" run sometime in the first quarter of the year, with exact dates to be determined, the executives said. O'Brien reruns will fill the gap until Fallon takes over.