CINCINNATI — W. Rodney McMullen will succeed David Dillon as chief executive officer of Kroger Co., one of North America’s biggest pharmacy operators, on January 1.

McMullen, 53, is currently president and chief operating officer of Kroger, which has about 1,950 pharmacies and generated prescription sales of more than $8 billion in its last fiscal year.

“As Kroger implements its strategic growth initiatives, the time is right for the transition of leadership,” said the 62-year-old Dillon, who will remain company chairman. He said McMullen “has played a leadership role in every major decision Kroger has made for the past 25 years, including the development and implementation of Kroger’s Customer 1st approach as well as our current growth strategy. He is ready to be CEO.”

Lead director Robert Beyer commented, “We are confident Kroger will continue its growth momentum during the transition and under Rodney McMullen’s leadership. Rodney has the right skills and experience to build on Dave’s accomplishments and leverage Kroger’s strong platform in the years ahead.”

McMullen, who has been president and COO since 2009 and a director since 2003, joined the chain in 1978 on a part-time basis on a stock crew. He held a variety of senior management positions including vice chairman; executive vice president of strategy, planning, and finance; and chief financial officer.