SAN FRANCISCO (AP) — Apple's top retailing executive is stepping down amid a slowdown in iPhone sales that has raised doubts about the company's future growth prospects.

The shake-up announced Tuesday ends Angela Ahrendts' five-year stint overseeing Apple's 506 retail stores and e-commerce operations. She is being replaced by Deirdre O'Brien, a longtime Apple executive who also runs the company's human-resources department. Ahrendts will remain with Apple until April.

During her 30 years at Apple, O'Brien also helped gauge product demand. That issue has become a problem now that customers are holding onto their current iPhones longer instead of buying the latest models. It's one reason Apple posted disappointing iPhone sales during the past holiday shopping season.

Although Apple sells iPhones and other products such as the iPad and Mac computer through a wide variety of merchants, its own elegantly designed stores have become a pivotal outlet, especially during the first few weeks after a new device hits the market.

"It was clear that Apple needed new strategies and a potential change on this front to catalyze demand in and outside the all-important retail stores," Wedbush Securities analyst Daniel Ives.

Apple didn't give a reason for Ahrendts' departure, saying only that she is leaving "for new personal and professional opportunities."

Ahrendts, 58, joined Apple amid great fanfare in 2014 after CEO Tim Cook persuaded her to leave a glamorous job running the fashion brand Burberry. To lure her away, Apple gave Ahrendts company stock valued at $70 million in 2014. In her last full year at Apple, she received a compensation package valued at $26.5 million, according to filings with the Securities and Exchange Commission.

Ahrendts' arrival at the Cupertino, California, company coincided with the rollout of the Apple Watch, which the company designed to be a fashion statement in addition to a wearable piece of technology.

While at Apple, Ahrendts engineered renovations of high-profiles stores in San Francisco, New York, Chicago and other cities in an attempt to transform them into hip places to hang out while shoppers checked out the company's latest innovations. Her lofty description of the stores as the equivalent of "town squares" became the subject of derision among some analysts and media commentators.