SHOPS in France will remain free to hold sales at times of the year that suit them, despite complaints from some retailers that the system is harming the industry and confusing consumers.
The flexible measures, called "floating sales" (soldes flottants) were introduced in 2008 in France's economic modernisation law and have now been extended for a further year.
Under the system, the winter and summer sales - which have strict start and end dates - run for five weeks instead of six, and shops can choose two other weeks to run sales elsewhere in the calendar.
The concept has been criticised by some retailers, who say it lessens the impact of the sales.
Fashion retailers' trade body FNH, which represents almost 45,000 shops around France, believes "floating sales" confuse consumers.
Group president Charles Melcer told Europe 1: "If someone buys an item of clothing and three days later it goes on sale, they rightly feel that they have been robbed."
However, research commissioned by finance minister Christine Lagarde and commerce minister Frédéric Lefebvre suggests the flexible sales have helped clothes shops boost their revenue by €93m over 18 months.
Their research also found that 56 per cent of consumers considered shopping in the sales to be "a budgetary necessity" and 71 per cent supported the flexible system.
The soldes are the only time of the year when shops are legally allowed to sell merchandise at a loss.
Retailers can run promotions at other times of the year, but the primary aim of the sales is to get rid of old stock.
The 2011 winter sales start in most areas of France on January 12 at 8.00 and end on February 15.
Six departments near the French border are free to set different dates: the Meurthe-et-Moselle, Meuse, Moselle, Vosges, Landes and Pyrénées-Atlantiques.