ABC News President Ben Sherwood sent the following note to the news division this morning announcing that Dan Harris will become a co-anchor of "Nightline:"

I am delighted to announce that Dan Harris is becoming a co-anchor of Nightline. Effective immediately, he joins Cynthia McFadden and Dan Abrams at the helm of our award-winning late night program which recently closed out the 2012-2013 season beating its competition on CBS in every demo and consistently improving ABC's performance at 12:35 am.

Bill Weir informed me this week that he is leaving ABC News for another opportunity in the news business.

Dan will continue to co-anchor the weekend edition of Good Morning America, a role he has held since October 2010. The show is posting its best ratings in years. Just last week GMA Weekend won the 2012-2013 season as the most-watched Saturday morning program in total viewers and Adults 25-54.

Dan is one of our most versatile anchors-covering many of the biggest news stories for all of our broadcasts since he joined the network in 2000, including mass shootings in Newtown, Connecticut, Aurora, Colorado and Tucson. He has covered natural disasters from Haiti to Myanmar to New Orleans. He has also reported from combat zones in Afghanistan, Israel, Gaza and the West Bank, and has reported from Iraq on six occasions.

Dan has led ABC News' coverage of faith, with a particular focus on the evangelical movement. He scored one of the first interviews with former pastor Ted Haggard after his sex and drugs scandal.

Dan has made it a priority to report on the world's most vulnerable populations, producing stories about child slaves in Haiti, youths accused of witchcraft in the Congo and predatory pedophiles who travel from the U.S. to Cambodia.

He has also covered endangered animals from Namibia, Madagascar, Papua New Guinea and Nepal. On the lighter side, this Murrow and Emmy award-winner has also reported extensively on his favorite subject: his beloved cats.

I want to take this opportunity to thank Bill for many years of contributions to ABC News and for his friendship. He helped launch GMA Weekend in 2004 and was named co-anchor of Nightline in 2010. A gifted writer and storyteller, Bill has taken our audience around the world, reporting from atop the Golden Gate Bridge and under the waters of the Great Barrier Reef. He has ventured where few have gone before including Foxconn in China giving viewers a rare glimpse inside Apple's factories.

Bill's style is singular; his voice unique; and we will miss him and, yes, his turkey frying safety tips. I know you all will join me in thanking him for his contributions and wishing him the best.

Ben