Verizon Communications Inc said yesterday it closed its $4.48 billion acquisition of Yahoo Inc’s core business and that Marissa Mayer, chief executive of the internet  company, had resigned.

The completion of the acquisition marked the end of Yahoo as a stand-alone internet company, a tech pioneer once valued at more than $100 billion.

Verizon, the number-one US wireless operator, is combining Yahoo with AOL, which it bought two years ago, to form a venture called Oath, led by AOL CEO Tim Armstrong.

“Given the inherent changes to my role, I’ll be leaving the company,” Mayer wrote in an e-mail to employees on Tuesday.

Armstrong told employees in a separate note that the combined company’s services “reach over a billion people each month.”

He said the “opportunity in front of us is not about the opinions from the pundits and it is not about the competition, it is about our ability to maniacally focus on delivering magical services to mobile enabled consumers.”

The closing of the deal had been delayed as the companies assessed the fallout from two data breaches that Yahoo disclosed last year.

Reuters reported last week that Verizon planned to cut about 2,000 jobs of the 14,000 employees at its Yahoo and AOL units.