By Rory Gallivan 
 

LONDON--The U.K.'s competition watchdog on Thursday said it conducted an investigation into supermarkets that found examples of pricing and promotional practices that could mislead consumers and be in breach of consumer law.

The Competition and Markets Authority, or CMA, said it will work with supermarkets to cut out practices such as running "was/now" promotions where the discounted price was advertised for longer than the higher price applied following the investigation, which was initiated in response to the consumer magazine Which?.

The problems the CMA found "are not occurring in large numbers across the whole sector and... generally retailers are taking compliance seriously to avoid such problems occurring," it said.

"We have found that, whilst supermarkets want to comply with the law and shoppers enjoy a wide range of choices, with an estimated 40% of grocery spending being on items on promotion, there are still areas of poor practice that could confuse or mislead shoppers," said Nisha Arora, CMA senior director, consumer.

"So we are recommending further action to improve compliance and ensure that shoppers have clear, accurate information," she added.

Write to Rory Gallivan at rory.gallivan@wsj.com; Twitter: @RoryGallivan

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