CINCINNATI — Kroger Co. chief executive officer Rodney McMullen assumed the additional title of chairman, succeeding David Dillon, on ­January 1.

McMullen and Dillon are credited with developing a long-term price investment strategy as part of the chain’s Customer 1st initiative that has enabled Kroger to deliver sustainable business growth and shareholder returns, while saving customers nearly $3 billion annually through lower prices.

This laid the foundation for Kroger’s growth plan, announced in October 2012, which expands Customer 1st by accelerating core business growth and improving the company’s connection with customers; expanding Kroger’s presence in new and existing markets; and innovating for unique competitive positioning.

“For Dave, Customer 1st — which truly put our customers at the center of how Kroger runs its business — was more than a successful business strategy,” said McMullen. “It was a philosophy that he believed and lived through his actions every day and, as a result, he inspired thousands of our associates during his many years of service to Kroger and Dillons companies. He understood that Kroger’s greatest asset is the trust that our customers, associates and shareholders have in our company. We are all the beneficiaries of Dave’s extraordinary leadership.”

Dillon, who was named chairman in 2004, was CEO from 2003 to 2013. Prior to that, he held a variety of executive positions at Kroger and Dillons, which merged in 1983.

During his tenure as CEO, Kroger added $45 billion in sales, created 53,000 jobs, reduced costs for eight consecutive years and returned $9.2 billion to shareholders through share repurchases and dividends, which were reinstated in 2006.

Kroger has also become a leader in supermarket sustainability under Dillon, reducing energy consumption in stores by 35% since 2000.