Twitter owner Elon Musk announced in a tweet on Friday that Linda Yaccarino, a veteran media executive who led advertising at NBCUniversal for more than a decade, will succeed him as the platform's next CEO.

"I am excited to welcome Linda Yaccarino as the new CEO of Twitter!" Musk wrote.

"[Yaccarino] will focus primarily on business operations, while I focus on product design & new technology," Musk continued. "Looking forward to working with Linda to transform this platform into X, the everything app."

Hours earlier Friday, NBCUniversal announced that Yaccarino "is leaving the company, effective immediately," according to a statement.

"It has been an absolute honor to be part of Comcast NBCUniversal and lead the most incredible team," Yaccarino said.

Musk had tweeted Thursday that he had picked someone for the No. 1 job, the position currently occupied by himself. But left crucial details, like the person's identity, vague.

Yaccarino has led advertising at NBCUniversal for more than a decade, leading a team of more than 2,000 people, according to her LinkedIn profile. That's larger than Twitter's estimated workforce, now about 1,500 employees, or roughly 20% of the company's size pre-Musk.

Before NBCUniversal, Yaccarino headed ad sales and marketing at Turner Broadcasting System, currently owned by Warner Bros. Discovery, for more than a decade.

In December, Musk polled Twitter users about resigning as its chief executive. "Should I step down as head of Twitter? I will abide by the results of this poll," he tweeted.

Of the 17.5 million responses, 58% said "Yes."

Musk and Yaccarino shared a stage weeks earlier

Yaccarino and Musk appeared on stage together at a marketing conference in Miami in April.

She pressed Musk about Twitter's new "Freedom of Speech, Not Reach" safety policy, aimed at preserving the "right to express their opinions and ideas without fear of censorship."

Musk said that if someone wants to say something that is "technically legal" but "by most definitions hateful," Twitter would allow it to stay on the site but behind a "warning label."

When asked by Yaccarino how Twitter will ensure advertisements don't appear next to negative content, Musk said the site has "adjacency controls" to prevent that from happening.

Twitter has seen advertising sales plummet in a harsh economic climate for tech companies and the media industry.

In the weeks following Musk's acquisition last fall, more than half of Twitter's top 100 advertisers fled the site, citing warnings from media buyers.

Advertising had accounted for the majority of Twitter's revenue before Musk took the company private, according to SEC filings.

Yaccarino is the second executive to leave the network in recent weeks. Its parent company, Comcast, ousted NBCUniversal CEO Jeff Shell after an employee filed a formal complaint accusing him of sexual harassment.

Yaccarino was set to participate in a key marketing presentation for NBCUniversal next week in New York commonly called the "upfronts," where media companies aim to persuade brands to spend big dollars on commercial time.