Apple Appoints New Chief Operating Officer Jeff Williams has effectively been Apple's COO for some time. The company also announced other staff changes.

Apple on Thursday named a new chief operating officer, Jeff Williams, a longtime employee who has since 2010 managed the company's supply chain, service, and support.

Williams has effectively been Apple's COO for some time, but CEO Tim Cook has left the title unclaimed since he vacated it to take the reins from an ailing Steve Jobs in 2011. Williams first joined Apple (AAPL -0.65%) in 1998 as head of worldwide procurement and was named vice president of operations in 2004. He ascended to his previous role in five years ago.

"Jeff is hands-down the best operations executive I've ever worked with, and Johny's team delivers world-class silicon designs which enable new innovations in our products year after year," Cook said in a statement.

That's not all. Apple also announced:

• That Philip Schiller, its senior vice president of worldwide marketing, will expand his responsibilities to manage the company's App Store
• That Tor Myhren will join Apple in the first calendar quarter of 2016 as vice president of marketing communications, reporting to CEO Tim Cook
• That Johny Srouji will join Apple as senior vice president for hardware technologies

Myhren joins from Grey Group, where he has served as chief creative officer and president of Grey New York, and succeeds Hiroki Asai, who earlier announced plans to retire after 18 years at Apple. Srouji, who joined Apple in 2008, was previously in charge of development of Apple's systems-on-a-chip, the hardware that powers mobile devices like the iPhone and iPad.

"We are fortunate to have incredible depth and breadth of talent across Apple's executive team," Cook added.