ABC is looking for a new producer to open the network for business each morning.

The abrupt departure of Michael Corn, the seasoned news producer who has managed the network’s flagship A.M. franchise, “Good Morning America,” since 2014, means ABC News is suddenly working a little harder to keep the program on its current path. “GMA” is the nation’s most-watched morning-news program, and is locked in a scorched-earth battle for dominance with NBC’s “Today,” which continues to command a lead among the viewers most coveted by advertisers in news programs, people between 25 and 54.

The job is a critical one at ABC and its parent company, Walt Disney Co. “GMA” generated $293.6 million in advertising in 2020, according to Kantar, a tracker of ad spending, compared with $357.6 million for NBC’s “Today” and $185.4 million for “CBS This Morning” on CBS. And the show has recently been expanding. In 2018, ABC News launched an afternoon extension of the program that, after a shaky start, has functioned as sort of a news update for midday viewers. In 2019, ABC expanded the hours of the show’s Saturday broadcast, part of a bid to get more stations to run the program across the U.S.

Corn’s sudden exit, revealed Thursday, surprised the show’s staffers, according to people familiar with the matter, and ABC News has not publicly explained the reason for the split, even as chatter about what may have happened has begun to swirl across various TV newsrooms. “Michael Corn no longer works for ABC News,” the company said Thursday. Corn is a ABC News veteran who has worked alongside Diane Sawyer as well as “GMA” anchors Robin Roberts, George Stephanopoulos and Michael Strahan. He was seen as a potential internal candidate for the role of ABC News president. That job was filled this week by senior CBS News executive Kim Godwin.

Corn’s departure adds to new tensions at the news division, which has for some time enjoyed a period of relative calm. “GMA” and “World News Tonight” both command bigger overall audiences than their competitors at CBS and NBC.  The newsmagazine “20/20,” has gained traction in recent months by focusing on longform stories that translate well on streaming venues. And ABC News has been ramping up its live-streaming efforts like ABC News Live, while integrating digital and linear personnel.

Suddenly, the path ahead is less sure. The executive who supervised past ABC News activity, James Goldston, is gone. And Godwin will start her work in May with some urgency, having to find a new commander for the A.M. franchise.

The new president is likely to have a firm grip on the task at hand. Godwin was closely involved with two recent searches for a new executive producer at “CBS This Morning.” She was part of the team that awarded the job to Diana Miller in April of 2019, and, subsequently, to Shawna Thomas in January of this year. She will know which candidates may be available and what their strengths and weaknesses may be.

Among the potential candidates for the role could be two of the top producers at “GMA.” Simone Swink oversees the second hour at the morning program, while Christine Brouwer supervises the first. And then there are a range of executives with prior experience that could make them a good fit for the job. Godwin, the incoming ABC News president, would be familiar with Ryan Kadro, for example, a former executive producer for “CBS This Morning” who has been a recent candidate for roles at ABC, according to people familiar with the matter.