They fell 10% on average but champagne was badly affected, down 34%. Bordeaux, the biggest seller in red wine, fell 8.6%, though white wine was up by 1%.
These autumn sales usually make up 15% of supermarkets’ annual sales – around €100million for Leclerc alone.
A study by analysts Nielsen of the foires in September and October across supermarkets and corner shops blames the Loi EGalim which came in at the end of last year.
It raised the level at which shops are deemed to be selling at a loss, which is not allowed, as well as banning previously popular buy-one-get-one-free offers.
The law saw sale prices rise about 10% and limited discounts to 34%. It aimed at a better balance of price and quality and to stop price bullying of producers.
Charles Cousineau, head of wine at Auchan where foire sales were down 26%, said: “There is not just one explanation. It is true of champagne, where sales are driven by offers, and Bordeaux, where there is no more ‘buy-three-get-three-free’, but it comes after years of red wine sales falling.
“The best promotion for wine is a Guide Hachette endorsement or a concours medal.
“They are big sellers, so we must aim for quality. People also want to be told the wine’s story, giving a reason to buy.
“We are pushing more white wine, as buyers want fresher wine, and sparkling such as crémants to give freshness and value for money. Not forgetting beer, the No1 rival to wine for many men.”
Poorer sales will not end the foires but shops now spread offers across the year – Black Friday, Christmas – and bank on aids such as loyalty cards and contests.
They also try new ideas, such as Super U’s plan for a “calm” period one afternoon a week with soft lights and quiet music to help autistic people shop.
The law has also hit products such as foie gras, where offers give the producers their only publicity. Autumn sales make up two-thirds of purchases, but they are 25% down.
The government has begun talks with unions and business about late-night supermarket opening. Casino continues to roll out a strategy of opening hypermarkets without checkout staff late at night and on Sundays. Limoges and Puy-en-Velay will be the latest, by the end of the year.