The Competition and Markets Authority (CMA) was responding to a "super-complaint" from a consumer watchdog that said it had identified "misleading and confusing" pricing tactics over seven years in areas such as multi-buy offers at the likes of Tesco (>> Tesco PLC) and Asda, which is part of Wal-Mart Stores (>> Wal-Mart Stores, Inc.).

The Which? consumer watchdog had said that many supermarkets were creating the illusion of savings that did not exist.

The CMA said, however, that any problems stemming from confusing promotional practices were not widespread and that generally the retailers were working well to avoid confusing their customers.

"We have found that, while supermarkets want to comply with the law and shoppers enjoy a wide range of choices ... there are still areas of poor practice that could confuse or mislead shoppers," the CMA's Nisha Arora said on Thursday.

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

Britain's "Big Four" supermarket chains, Tesco, Asda, Sainsbury (>> J Sainsbury plc) and Morrisons (>> WM Morrison Supermarkets PLC), have become embroiled in a price war as they battle to hold on to sales being lost to increasingly popular German discounters Aldi [ALDIEI.UL] and Lidl [LIDUK.UL], whose no-frills offers have struck a chord with Britons.

Examples of confusing offers cited by Which? included pizzas priced at 1.50 pounds ($2) at Asda being increased to 2 pounds in a two-for-3 pounds multi-buy offer.

The CMA said it would work with the industry to address any problem areas.

(Reporting by Kate Holton; Editing by David Goodman)