CHESAPEAKE, Va. — Michael Witynski has been promoted to president and chief operating officer of Dollar Tree Inc.’s 6,200-store Dollar Tree chain.

“Mike is an accomplished executive with more than 36 years of experience in retail,” Dollar Tree chief executive officer Bob Sasser said in a statement. “Dollar Tree is a growth company, now larger and more diversified than ever before. We have nearly 14,500 stores with plans to open 650 new stores this year. With Mike in this leadership role as president and chief operating officer of Dollar Tree and Duncan Mac Naughton leading Family Dollar, we are confident we have the right executives in place to lead us through the next phases of growth.”

A Dollar Tree veteran, Witynski has served as chief operating officer since July 2015, and he previously served as senior vice president of stores. Witynski joined Dollar Tree in 2010. Before that, he held executive leadership positions at Shaw’s Supermarkets and Supervalu Inc.

Witynski will continue to report to Gary Philbin, enterprise president at Dollar Tree. In his new role, Witynski will be responsible for merchandising, marketing and store operations for more than 6,200 Dollar Tree bannered stores in the United States.

“I am very pleased to announce the promotion of Mike Witynski,” Philbin said. “Mike has been a key leader and a major contributor to Dollar Tree’s growth and sector-leading profitability since joining the Company in 2010. Through his consistent focus on store execution and delivering results, Mike has developed and led key initiatives to drive market share through new store growth while increasing store and associate productivity.”