NEW YORK — Best Buy is shuttering all 250 of its small-format mobile phone stores in the U.S., saying the locations have become less profitable.

A memo from the CEO to employees says the stores will close by the end of May and every effort will be made to retain the workers.

The nation's largest consumer electronics chain launched the stores more than a decade ago, before Apple's iPhone was launched. The mobile phone business was growing quickly, with high profit margins.

But it said the business has matured and running the mobile stand-alones cost more than its larger stores, and that 85 percent of the stand-alones are within 3 miles of a big box store.

Best Buy says the stand-alone stores accounts for just over 1 percent of the company's total revenue.