NBCUniversal’s longtime ad sales chief Linda Yaccarino has resigned, effective immediately, the company announced in a press release Friday morning. While a reason for the executive’s sudden departure wasn’t given, the move follows multiple news outlets reporting that the advertising maven is in talks to step in as CEO of Elon Musk’s Twitter.

“We are grateful for Linda Yaccarino’s leadership of NBCUniversal’s Advertising Sales business, and for the innovative team and platform she has built,” said Mike Cavanagh, president of Comcast Corporation, NBCUniversal’s owner, in a press statement. “Linda has made countless contributions to the company during her twelve year tenure, and we wish her the best.”

In a tweet posted Thursday afternoon, Musk said that he had selected a chief executive to replace him at the social media company in about six weeks’ time, though he didn’t disclose a specific name. The Tesla and SpaceX entrepreneur will transition to being Twitter’s executive chair and chief technology officer overseeing product, software and system operations. 

Yaccarino leaves NBCUniversal in the thick of the upfronts season, a period where the media and entertainment giant locks in lucrative advertising deals for the months ahead. The executive has been a key presenter at such events in the past and was expected to have a major role again for NBCUniversal’s presentation at Radio City Music Hall on Monday, May 15. NBCUniversal’s pitch this year will focus heavily on the strengths of its streaming service Peacock. The company also recently participated in the more digitally oriented NewFronts.

Mark Marshall, NBCUniversal’s current president of advertising sales and client partnerships, will step up as interim chair of NBCUniversal’s Advertising and Partnerships group. Marshall reports directly to Mark Lazarus, chairman of NBCUniversal Television and Streaming.

Yaccarino is credited with helping usher NBCUniversal into the digital and streaming age, along with fostering strong relationships with brands, agencies and platforms. NBCUniversal has had a major presence on Twitter for years for events like the Olympics. 

Twitter, meanwhile, has faced severe challenges under Musk, who acquired the platform for $44 billion last year. Advertisers have reportedly fled the platform in droves, put off by changes to Twitter’s verification system, technical glitches and the executive’s provocative personality. Musk earlier this week engaged with conspiracy theorists on Twitter who baselessly questioned whether the identity of a mass shooter in Allen, Texas, was a government “psyop,” an example of the types of misinformation-mongering brands want to avoid.

Hiring someone like Yaccarino could be the start of rebuilding a bridge with the advertising community, though the road ahead could be long for Twitter regardless. 

“There are very few people who wouldn’t be just seen as a figurehead CEO of Twitter and Linda Yaccarino is one of them. She’s a well-respected force in the industry whose credibility with advertisers speaks for itself,” said Forrester research director Mike Proulx in emailed comments. 

“Unfortunately, the solve isn’t just an advertising issue, it’s also a product issue and therein lies the rub for anyone who takes on Twitter’s CEO role,” Proulx added. “Musk has fundamentally altered the trajectory of Twitter as a product and as a community — many argue for the worst. While he’s stepping back from the CEO title, Musk is far from likely to step back from calling the product shots.”