Chris Cuomo will be working the early shift as news anchor of "Good Morning America" starting next month.
Along with delivering "news block" reports throughout the weekday broadcast, Cuomo will serve as principal substitute anchor, the network said. He also will contribute news reports and travel to cover breaking news.
Cuomo, 36, will remain at "Primetime," where he became co-anchor in April 2004, and also continue as ABC News' senior legal correspondent.
He will relieve Roberts, who has continued her news-anchor role since being promoted to an anchor of the broadcast in May 2005.
Before joining ABC News six years ago, Cuomo was a correspondent for Fox News Channel and Fox network's "Fox Files." An attorney and a native of New York, he is a son of former New York Gov. Mario Cuomo.