Sainsbury's, Britain's second largest supermarket group which has agreed to buy smaller rival Asda, was again the worst performer of the country's big four grocers in the latest 12-week period, industry data showed on Tuesday.
In April Sainsbury's agreed a £7.3 billion (€8.1 billion) cash and shares takeover of Walmart-owned Asda, the No. 3 player - a combination that could overtake Tesco as Britain's biggest supermarket group.
Sales at Sainsbury's rose 1.2% in the 12 weeks to Aug. 12, market researcher Kantar Worldpanel said.
Morrisons was alone among the big four in maintaining its market share, the other three continue to lose ground to German-owned discounters Aldi and Lidl, which are opening new stores aggressively.
Aldi and Lidl's sales rose 12.6% and 8.6% respectively.
Sales at the Co-operative rose 7.8%, its fastest rate of growth in nearly seven years.
Total grocery market growth was 3.5%, while grocery inflation for the 12 week period was 1.9%, Kantar Worldpanel said.