NEW YORK - ABC News says Dan Harris is replacing Bill Weir as a co-anchor of "Nightline," effective immediately.
Harris will remain on the weekend edition of "Good Morning America," which he has co-anchored since 2010.
Since joining ABC News 13 years ago, Harris has covered mass shootings, natural disasters and global trouble spots, reporting from Iraq on six occasions.
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.
The network says Weir is leaving ABC News for an undisclosed job elsewhere in the news business.
He has been a "Nightline" co-anchor since 2010 and is a former co-anchor of the weekend "GMA."
"Nightline" airs weeknights at 12:35 a.m. Eastern time.