Walmart has promoted Duncan Mac Naughton to chief merchandising officer for its U.S. stores.

Mac Naughton, who was executive vice president of merchandising for Walmart U.S., now oversees all merchandise categories across 3,700 stores in the retailer's U.S. business. As part of a merchandising realignment last fall, he was given responsibility for overseeing consumables and health and wellness for Walmart U.S., as well as Walmart.com.

BENTONVILLE, Ark. — Walmart has promoted Duncan Mac Naughton to chief merchandising officer for its U.S. stores.

Walmart has promoted Duncan Mac Naughton to chief merchandising officer for its U.S. stores.

The discount store giant said Friday that the move is effective immediately. Mac Naughton, who was executive vice president of merchandising for Walmart U.S., now oversees all merchandise categories across more than 3,700 stores in the retailer’s U.S. business.

He continues to report to Bill Simon, president and chief executive officer of Walmart U.S.

"Duncan has distinguished himself with a proven record of success in every organization that he has worked in, including Walmart in the United States and Canada," Simon said in a statement. "He is a strong steward of our culture, and he understands that merchandising is at the very core of our business. Duncan is committed to giving our customers a breadth of assortment, national brands and everyday low prices."

Mac Naughton joined Walmart in the fall of 2009 as chief merchandising officer for Walmart Canada, coming over from supermarket operator Supervalu Inc., where he was executive vice president of merchandising and marketing. And as part of a merchandising organization restructuring announced by Walmart last September, he was named executive vice president of merchandising for Walmart U.S., in which he was responsible for consumables, health and wellness, and Walmart.com.

Before his most recent role at Supervalu, Mac Naughton held leadership positions at Kraft Foods Inc., H.E. Butt Grocery Co. and Albertsons Inc.

"I am pleased to have the privilege to lead Walmart U.S. merchandising," Mac Naughton stated. "We remain focused on ensuring that our assortment exceeds our customers’ expectations, both in stores and online. While much has been accomplished, we are working closely with our suppliers to deliver the products and the brands our customers are looking for at Walmart’s everyday low prices.

"Our team is more committed than ever to our mission of saving people money so they can live better," he added. "We intend to make the shopping experience more fun for our customers through increasing promotional intensity by effectively utilizing action alley. In the end, it is about having great products at every day low prices."

Mac Naughton takes over the role formerly held by executive vice president and chief merchandising officer John Fleming, who left Walmart in August. The retailer unveiled the move in early July, just days after announcing Simon’s appointment as the head of Walmart U.S.

Under the merchandising realignment announced last fall, Walmart created four core merchandising areas, each consisting of similar categories and headed by an executive vice president.