David Muir will start to lead breaking-news duties at ABC News, a new effort by the Walt Disney unit to rework an unorthodox arrangement involving two of its top anchors.

Under a new structure, Muir will largely handle the bulk of ABC News’ special reports and news of national importance, while George Stephanopoulos, the “Good Morning America” and “This Week” anchor may shepherd similar efforts in the morning, according to three people familiar with the matter. Since 2014, when Diane Sawyer stepped down from her tenure on “World News Tonight,” Stephanopoulos was recognized as ABC News’ “Chief Anchor,” and had led coverage of events of critical importance, presidential debates and elections. He has often been paired with Muir and Linsey Davis, an anchor who leads a program on the network’s streaming-video hub, ABC News Live. That title will no longer be utilized.

ABC News declined to make executives available for comment. CNN previously reported the new anchor structure.

The new arrangement recognizes Muir’s continued momentum at ABC News, where his “World News Tonight” has surged in the ratings since he took the program over in 2014. During Muir’s tenure, the evening-news broadcast has outmaneuvered NBC’s “NBC Nightly News,” which previously led the three networks’ evening efforts. ABC News executives approached Muir about the chance to lead breaking coverage two years ago, according to one person familiar with some of the negotiations involving the anchors, and suggested Muir would likely take the new duties after the 2020 election.

Under the terms of an extended contract, Stephanopoulos will get new production duties, leading a new program on politics for Hulu and devising four hour-long specials for primetime.

The new anchor arrangement comes as ABC News is in a period of flux. James Goldston, ABC News’ president, is slated to depart the unit by the end of the month, and Disney has not identified a successor. ABC News is under the aegis of Disney executive Peter Rice, who has set up an interim structure that will have a suite of senior ABC News executives and producers running the operation for an as-yet-undetermined amount of time.

The broadcast networks have in recent years seemed split about how best to deploy their morning and evening anchors at important news events.  The evening-news anchor has nearly always been the correspondent assigned to represent the network at times of major news and crisis moments. CBS News’ relies on Norah O’Donnell, for example.

And yet, the morning-news shows represent a critical profit center for CBS, ABC and NBC. When ABC News gave Stephanopoulos his chief anchor role, it was at the time seen as a nod to the growing importance of morning TV over the evening news, which had suffered ongoing audience declines. In the past year, with more people staying close to home due to the coronavirus pandemic, the evening-news shows have experiences significant surges, reversing past trends.

NBC News in recent months has managed to thread the needle, relying on both evening-news anchor Lester Holt and “Today” co-anchor Savannah Guthrie to lead many of the news division’s top broadcasts.