J Sainsbury and John Lewis's Waitrose are the only Top Six British grocery chains currently resisting pressure from discounters Aldi and Lidl to expand their market share, monthly industry data showed on Tuesday.
Though data and surveys have indicated the outlook is improving for UK consumer spending, retailers are generally still wary as inflation continues to outpace wage rises.
In recent weeks, store groups including market leader Tesco and No. 3 Sainsbury's, have highlighted the fact that consumers' disposable income is still falling.
Sainsbury's and Waitrose, the UK's No. 5 grocer, outperformed the market with year-on-year sales growth of 3.7 percent and 7.6 percent respectively in the 12 weeks to Oct. 13, narrowly expanding their market share, researcher Kantar Worldpanel said.
However, their growth was dwarfed by a 31.7 percent sales rise at Aldi, which gave it a record market share of 3.8 percent against 3.0 percent a year earlier.
Aldi more than doubled its profit in its UK business in 2012, as it attracted 1 million more shoppers and got existing customers to spend more.
"The retailer has done a particularly good job in conveying its competitive pricing message through its 'Like Brands Only Cheaper' and subsequent 'Swap and Save' campaigns - both of which have given the supermarket a clear point of difference," said Kantar director Edward Garner.
Lidl also kept up its strong run with sales growth of 13.1 percent and a market share of 3.0 percent, up from 2.7 percent.
The trend for higher- and lower-end chains to gain at the expense of the middle ground was clear as the No. 1, 2 and 4 grocery chains by sales - Tesco, Wal-Mart's Asda and Morrisons - all recording sales growth of 1.0 percent or less, against a 3.0 percent market average.
Last month, Tesco reported flat underlying sales for its second quarter, while Sainsbury's posted a second quarter rise of 2.0 percent, albeit for a different period.
Kantar said grocery inflation remained at 4.2 percent for the 12 week period.
