Charlie Gibson, ABC's World News Tonight

Charles Gibson's last day behind the desk of ABC's World News Tonight will be Dec. 18, TVGuide.com has confirmed.

World News executive producer Jon Banner first broke the news on ABC News' World Newser blog. He promised that the network had plans to send Gibson off in style.

Watch videos of Charles Gibson

"We're going to spend a good deal of time during his final week on the air looking back at the stories Charlie covered, hearing again from some of the remarkable people he interviewed, and paying tribute to our friend and colleague, and the enormous contribution he has made to ABC News over the last three decades," Banner wrote.

Gibson, 66, has hosted World News since 2006. He'll be succeeded by his former Good Morning America co-host, Diane Sawyer. ABC wouldn't confirm her start date, but the New York Times says it'll be Monday, Dec. 21.