Keith Olbermann signed for four more years as host of MSNBC’s “Countdown With Keith Olbermann.”

Mr. Olbermann, who has swayed MSNBC’s prime-time tone to the left, also picks up a chance to do occasional essays for “NBC Nightly News” and host two “Countdown” specials each year.

An MSNBC spokesperson declined to comment on speculation that Mr. Olbermann accomplished his goal of effectively doubling his salary to some $4 million per year.

“Keith Olbermann is a tremendous talent and a superb broadcaster,” NBC News President Steve Capus said in the announcement Thursday. “He is an asset to NBC News and the timing of this announcement couldn’t be better given the momentum Keith’s program is enjoying right now.”

Mr. Olbermann returned in 2003 to MSNBC, which he had left in 1998, unhappy with the night-after-night focus on then-President Clinton’s affair with Monica Lewinsky. Viewership for “Countdown,” executive produced by Izzy Povich, in January averaged 715,000 viewers, 283,000 of them in advertisers’ preferred news demographic of 25 to 53 years old. That represented increases of 85 percent and 89 percent year to year in those age groups, respectively.

“I’m delighted we can continue ‘Countdown’ and continue to try to hold politicians and other newsmakers accountable for what they are doing, or not doing,” Mr. Olbermann said in a prepared statement.

One segment from Mr. Olbermann’s show inspired the book “The Worst Person in the World,” last year. Another book, based on his “Countdown” “Special Comments,” will be published next winter.

(Editor: Baumann)