NEW YORK -- ABC News says Dan Harris is joining "Nightline" as a co-anchor, succeeding Bill Weir, who's headed to CNN.
Harris will remain on the weekend edition of "Good Morning America," which he has co-anchored for three years.
Effective immediately at "Nightline," he replaces Weir, who will join CNN next month as an anchor and its chief innovation correspondent.
Weir had been a "Nightline" co-anchor since 2010 and is a former co-anchor of the weekend "GMA." He'll work with producers to develop original programming across the CNN schedule, the network said.
"Bill's range, sensibilityand curiosity set him apart," CNN Worldwide president Jeff Zucker said.
Harris, since joining ABC News 13 years ago, has covered mass shootings, natural disasters and global trouble spots, reporting from Iraq six times. ABC News president Ben Sherwood called him one of the network's "most versatile anchors."
Harris joins Cynthia McFadden and Dan Abrams at the anchor desk of the late-night news program.
"Nightline" airs weeknights at 12:35 a.m. Eastern time.