The supermarket group continues to lose market share to its competitors, as American-owned Asda wins more customers

Tesco's loss of market share to rival supermarket groups accelerated during January, The Times has learnt.

Industry data published last night showed that in the 12 weeks to January 25, Tesco's market share was 30.7 per cent - down from 31.2 per cent in the same period a year earlier.

At the same time, Asda's market share rose from 16.9 per cent to 17.2per cent, while the Morrisons chain's share rose from 11.6 per cent to 11.9 per cent.

However, the less widely circulated four-weekly data also compiled by TNS WorldPanel, the industry analyst, suggests that the rate at which Tesco is losing market share accelerated in the first month of the year.

The TNS sales data for the four weeks to January 25 show that Tesco had 30.3 per cent of the market, down from 30.6 per cent in the same period last year.

At the same time, the American-owned Asda increased its market share to 17.8 per cent, from 17.2 per cent in 2008, while Sainsbury's and Morrisons were unchanged at 16.3 per cent and 11.9 per cent, respectively.

However, a direct comparison of till rolls with a year ago shows that all three of Tesco's main rivals outpaced it in the four-week period, with Asda's sales up 11.7 per cent on a year earlier, sales by Morrisons up 8.4 per cent and Sainsbury's sales up 7.3 per cent. Tesco's till takings, by comparison, rose by only 6.5 per cent.

In pure groceries - stripping out non-food sales at the supermarkets - Tesco's decline appears even starker. Its share of that market in the four-week period fell from 30.8 per cent a year ago to 30.3 per cent, with most of its lost share appearing to go directly to Asda and Morrisons.

The Times 4/2/09