The High Court has found that advertisements by Dunnes Stores comparing products with rival outlet Aldi amounted to a misleading commercial practice likely to deceive customers.
Mr Justice Brian Cregan said Dunnes Stores had infringed customer protection law and EU regulations in its comparative advertising with certain Aldi products.
Judge Cregan found that in relation to pricing labels on Dunnes' shelves on 14 out of 15 products, the company had infringed the regulations.
Those products included pork sausages, turkey breast mince, yoghurts, an orange drink, tomato ketchup, white sauce, tinned beef and chicken dog foods and dry cat food.
Aldi had claimed that in October and November 2013 Dunnes had infringed Aldi trademarks by displaying banners in several Supermarkets in Cork , Kerry, Kildare, Louth, Offaly and Waterford containing the words "Lower Price Guarantee" and "Guaranteed Lower Prices on all your Family Essentials every week".
It was claimed the advertising banners failed to comply with the Consumer Protection Act 2007 and the European Communities (Misleading and Comparative Advertising) Regulations 2007 on grounds including they failed to objectively compare one or more of the relevant and verifiable features of the Dunnes' products with those of Aldi Ireland.
The banners also conveyed the impression Dunnes' products generally, or its "Family Essentials" range, were cheaper than those of Aldi Ireland when there was "no basis" for such a claim, Aldi said.
Dunnes had denied the claims.
Mr Justice Cregan today found "shelf edge labels", claiming Dunnes prices for these products were lower than Aldi prices, did not objectively compare products meeting the same needs or intended for the same purpose.
He also said the advertisements included "the provision of false information" in relation to the 14 out of 15 comparative products, including information about the nature, composition, characteristics or ingredients of those products.
He concluded such information would be likely to cause the average consumer to make a transactional decision, which that consumer would not otherwise make and this was contrary to the Consumer Protection Act, 2007.
The advertisements were misleading because they were likely to cause the average consumer to be deceived or misled in relation to those 14 products.
He also found Dunnes omitted or concealed material information in relation to comparative advertisements that the average consumer would need to make an informed transactional decision.
The case was adjourned for two weeks to allow both sides consider the judgment before the court makes any orders.
Dunnes will also consider whether to seek a stay on any order in the event of an appeal.
Aldi issued a statement this afternoon, saying it is pleased with today's ruling "which further underscores customers' entitlement to clear, transparent and accurate information in comparative advertising to help them make properly informed decisions about what they buy".
