NBC ousted beloved "Tonight Show" host Jay Leno at the end of last season and gave the position to O'Brien to keep O'Brien from moving to another network.
NBC then gave Leno his own nightly, hour-long, 10 p.m. chat series, "The Jay Leno Show." When the prime-time series failed to be a strong lead-in for local news broadcasts, however, NBC announced it would push Leno's show back to 11:35 p.m., shorten it to 30 minutes and air "Tonight" at 12:05 a.m, followed by "Late Show with Jimmy Fallon" at 1:05 a.m.
However, O'Brien said Tuesday he will not remain on "Tonight" if it is moved to 12:05 a.m. NBC has not yet commented on his announcement.
"Conan does not currently plan on doing any more new shows after next week," an insider told People.com.
NBC said the show had long been scheduled to go on hiatus Jan. 25.
Copyright 2010 by United Press International.