J Sainsbury PLC, the second-largest player in the United Kingdom grocery market, saw a flat year-on-year sales performance in the period, while its market share fell to 16.5% from 16.8% a year before.
Despite being overtaken by Aldi, The Co-op saw a 2% boost, or £1,656 million of sales, well ahead of the market 1.7% growth, driven by strong own-label growth, McKevitt said.
He said that Aldi had attracted 826,000 more shoppers than the same period a year ago after it opened a large number of new stores.
Aldi increased its market share by 0.6 percentage points, with sales up 12.4% year on year, putting it behind the "big four".
Walmart's (WMT) continued to lose ground in the U.K.as low-priced competitors gain steam and inflation takes hold, industry figures from Kantar Worldpanel released Tuesday show.
"Just a decade [Aldi] accounted for less than 2% of the grocery market", said Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel.
Kantar Worldpanel reported today that Tesco's sales had grown 0.3 percent year-on-year in the 12 weeks ending January 29, marking the fifth consecutive period of growth for the blue-chip supermarket.
According to the survey, Morrisons was the fastest-growing retailer within the big four, increasing its market share for the first time since June 2015 with a sales uplift of 1.9% year-over-year. Total supermarket sales were up 1.7% on previous year, with eight of the nine major retailers seeing sales growth over the 12 weeks - Asda's sales dropped by 1.9%. This was slower than its previous rate, and its market share has been ebbed away 0.4 per cent compared to a year ago.
Overall, supermarket sales were up 1.7% year on year, Kantar said. Waitrose also saw good growth of 3.4%, while Lidl and Iceland also saw growth, of 9.4% and 8.6% respectively.
Kantar said supply issues affecting fresh produce over the last few weeks had affected sales.
Growing for the fifth period in a row, Tesco's sales were up 0.3% year on year as its market share fell to 28.1%.
Asda suffered a sales slide over the period, with sales falling by 1.9 per cent.
Kantar said rising prices continued into the new year, with inflation on a basket of everyday groceries climbing to 0.7%.
He added that if prices continue rise to at the same rate for the rest of the year shoppers will be around £27 worse off.