"For this winter we have a crisis scenario where Russia cuts gas supplies," Michel-Edouard Leclerc told France Info radio.
Under that scenario, "We could close some stores during certain hours," he added.
Leclerc heads Les Centres E. Leclerc, a cooperative association of about 600 retailers, which competes against Carrefour and Casino.
Its low-price policy has helped it become France's biggest food retailer by market share.
(Reporting by Dominique Vidalon; Editing by Kirsten Donovan)