Microsoft has hired Bill Stasior, the person who until recently was in charge of the Siri virtual assistant at Apple.

The move underlines Microsoft's focus under CEO Satya Nadella on emerging technologies like artificial intelligence.

In 2016 Microsoft established the Artificial Intelligence and Research engineering group in a reorganization. Months later the company added AI to its list of top priorities in its annual report. Last year Microsoft went further in another reorganization that placed some AI teams in the group working on Microsoft's Azure public cloud.

Since then Microsoft has made AI acquisitions that have brought in additional talent, including Bonsai, Lobe and Semantic Machines.

Stasior announced his job change by updating his resume on his personal website on Monday. The resume says he'll be corporate vice president of technology in the office of the chief technology officer, Kevin Scott. The Information reported on the move earlier on Monday.

A Microsoft spokesperson confirmed Stasior's hire. "Starting in August, he will work to help align technology strategies across the company," the spokesperson wrote in an email to CNBC.

Stasior was vice president for AI and Siri when he left in May, according to the resume. He had been at Apple since 2012. He said that he expanded the team from 70 engineers to more than 1,100 people and that he "played the leading role in bringing modern machine learning to Siri and Apple." Apple said in 2018 that Siri was being actively used on more than 500 million devices, and earlier this year the company said that Siri would sound more natural in the forthcoming iOS 13 release. Apple previously made gains in this area through AI work.

Prior to his time at Apple, Stasior was one of the top executives at Amazon. He previously worked at AltaVista and Oracle. Stasior didn't respond to a request for comment.

Javier Soltero, the person who was leading the Microsoft's Siri competitor, Cortana, left last year. Earlier this year Cortana was decoupled from the search box in Microsoft's Windows 10 operating system.

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