Conan O'Brien Conan O'Brien

Conan O'Brien isn't the king of late night after all.

NBC issued a news release calling O'Brien "the new king of late night" after O'Brien's Tonight Show, in its first week, beat The Late Show with David Letterman in ratings.

See pictures of Conan through the years

Since then, Letterman has bounced back. NBC's head of late night, Rick Ludwin, said Wednesday at the Television Critics Association fall TV tour that the news release was "premature."

"There were those who predicted that Conan was not going to be broad-based enough to work at 11:30, and we were so thrilled with the numbers for the first week that far exceeded our expectations, that we used that phrase in that headline, and that was premature," Ludwin said.