UK's 'big four' grocers lose more ground

London - All of Britain's so-called "big four" supermarkets saw sales fall over the last 12 weeks in an overall market that grew marginally, with discounters continuing to take share from their bigger rivals, industry data showed on Tuesday.

Kantar Worldpanel said Asda, the British arm of US retailer Wal-Mart, suffered the biggest sales fall over the 12 weeks to July 19 with a decline of 2.7%.

That meant Sainsbury's regained its No. 2 status with a market share of 16.5% compared with Asda's 16.4%, even though its sales fell 0.3% in the period.

Market leader Tesco's sales declined 0.6%, while No. 4 player Morrisons' fell 0.1%.

In contrast, discounters Aldi and Lidl posted sales growth of 16.6% and 11.3% respectively, taking their market shares up to 5.6% and 4.0%.

Overall grocery sales increased by 0.8% over the 12 weeks compared with a year ago, while grocery deflation was 1.6%.