Amazon.com Inc. on Wednesday told Reuters it plans to close all 68 of its physical book stores, pop up shops and "4-star" stores in the United States and United Kingdom, ending some of its longest-running experiments in physical retail.

The news marks a turning point for a company that started out as an online bookseller, disrupting brick-and-mortar incumbents such as Borders and Barnes & Noble, only to open its own physical shops decades later.

Customers can find books, home goods, toys and electronics at Amazon's 4-star stores.

Amazon said physical retail remains an important way for it to reach shoppers and said it will continue to work on other concepts, such as its recently announced fashion store in greater Los Angeles and cashierless grocery stores.

The retailer said it was working to identify new roles within the company for employees at the shops it would close, such as placing them at nearby Amazon store locations. Workers who decide against remaining with the company would receive severance, Amazon said.

The Seattle-based company said closure dates will vary by location and that it will make customers aware via in-store signage.