CITY OF COMMERCE, Calif. — 99 Cents Only Stores LLC announced the promotion of Jack Sinclair to the role of chief executive officer.

Sinclair succeeds Geoffrey Covert, who is retiring.

The deep-discount retailer also announced the appointment of Jason Kidd as president and chief operating officer, reporting to Sinclair. Kidd joined 99 Cents Only Stores in 2014 as senior vice president of store operations.

Sinclair joined the company in 2015 as chief merchant. He has worked with Covert to bolster the company’s finances and position it for growth, 99 Cents Only Stores said in a statement.

“Jack is deeply committed to 99 Cents Only Stores and has been a tremendous advocate for our associates, customers and communities,” Covert said.

Covert’s retirement caps a 44-year career in the grocery retail sector. Since his appointment as CEO in September 2015, 99 Cents Only Stores has outpaced the industry through a focus on enhancing its merchandising selection and improving the customer shopping experience, the company said. Operating momentum achieved during Covert’s reign was instrumental in facilitating a three-year extension of the company’s capital structure, announced in December, the company noted.

Sinclair has 35 years of retail experience in the United States and the United Kingdom. He led Walmart’s grocery business from 2007 to 2015. Earlier, he spent 14 years at Safeway PLC in London. Since coming to 99 Cents Only Stores, Sinclair has endeavored to refocus the merchandising team on its core mission of providing exceptional value with top-name brands, closeouts, fresh produce and seasonal offerings, the company said.

“99 Cents Only Stores is one of the most iconic and unique brands in retail today,” Sinclair said. “I am privileged to serve with a team that has laid a solid foundation for success and that delivers unparalleled value and a unique customer experience.

“We look forward to continued growth, welcoming new customers to our existing stores and introducing our stores to new communities. We have ambitious goals, and our growth trajectory is just beginning.”

In other moves, the company said Norman Axelrod, a director since 2012, has been named board chairman, succeeding Andrew Giancamilli, who retains his seat on the board. Felicia Thornton, the company’s chief financial officer, was named vice chair.