France's fourth biggest supermarket group Systeme U said it would also sell at cost price, starting in October, but only over some weekends, as it could not afford to do it every day.
Its chief executive, Dominique Schelcher, said fuel margins were on average about two euro cents (拢0.017) per litre.
At the weekend, French president Emmanuel Macron said he would ask the fuel industry to sell at cost price and would provide 100 euro (拢87) grants to the poorest workers who drive to work.
The president said he would meet industry representatives this week to ask them not to charge a profit on fuel. The government floated the idea of adapting the law so that fuel could be sold at a loss, but the plan faced strong opposition from distributors.