PARIS, Dec 16 (Reuters) - Retailer Carrefour's French stores could be disrupted on Saturday as staff protest against working conditions, notably plans to extend night shifts, in the run-up to Christmas.
The CGT union has called for a one-day action on Dec. 18, with workers encouraged to stop work, strike, distribute leaflets or sign a petition, it said on its website.
Carrefour, Europe's largest retailer, would not comment on the likely impact of the action, aimed at all its French stores.
The company's homew market accounted for 43 percent of group net sales of 86 billion euros last year.
Domestic rival Auchan told Reuters on Wednesday it made roughly 15 percent of its annual revenue in December.
Auchan France also said December sales could be hit after heavy snow led to store closures last week.
A Carrefour spokeswoman said on Thursday Carrefour had been "impacted" by the snow but would not provide detail. (Reporting by Dominique Vidalon; Editing by Dan Lalor)