NBCUniversal global advertising chief Linda Yaccarino has resigned to join Twitter as its next chief executive.

Twitter owner Elon Musk confirmed the hire in a tweet Friday.

“I am excited to welcome Linda Yaccarino as the new CEO of Twitter!” Musk tweeted. He said she “will focus primarily on business operations, while I focus on product design & new technology.”

He added, “Looking forward to working with Linda to transform this platform into X, the everything app.”

The announcement comes a day after Musk said via Twitter that he would step down from the role and that there would be a new CEO of the social media website, although he didn’t name the new person. Musk said in his tweet the person would start in about six weeks.

Yaccarino joined NBCUniversal in 2011 and had risen to the top of the company’s global advertising business. On Monday, the ad chief was slated to take part in NBCUniversal’s Upfront event at Radio City in New York – the sales presentation the company, along with its media peers, makes to the advertising industry every year in May.

The longtime ad executive brings a wealth of relationships with top chief marketing officers and other advertising executives to Twitter at a time when the platform has seen advertisers flee – therefore losing billions of dollars – after Musk’s takeover last year.

Musk completed his $44 billion acquisition of Twitter in October of last year. Soon after, he fired the company’s top brass and laid off thousands of employees.

Many companies halted their ad spending on the platform since Twitter has seen an increase in offensive speech and rhetoric, as several advocacy groups have documented. In an attempt to make up for the loss of ad revenue, Musk created a new subscription service, Twitter Blue, which offers features such as the ability to compose longer tweets.

Yaccarino and Musk sat together in a keynote interview at a marketing conference in Florida in mid-April. During the conversation, the two discussed the role marketers play in the future of Twitter, as well as its position in the cultural conversation.

During the conference, Musk reportedly tried to reassure advertisers that Twitter was a respectable place for their brands.

Yaccarino’s exit from NBCUniversal comes weeks after Jeff Shell was ousted as the company’s CEO after admitting to an inappropriate relationship with an employee. Rather than replacing Shell, NBCUniversal’s top executives will report to Mike Cavanagh, president of parent company Comcast.

On Friday, NBCUniversal said Yaccarino would leave the company, effective immediately, and Mark Marshall, the current president of advertising sales and client partnerships would become interim chairman of the company’s advertising and partnerships group.

Marshall will report to Mark Lazarus, chairman of NBCUniversal Television and Streaming. Lazarus and Marshall are likely to take part in NBCUniversal’s Upfront presentation on Monday, CNBC’s David Faber and Julia Boorstin reported Friday.

Disclosure: NBCUniversal is the parent company of CNBC.