Asda, the UK arm of Wal-Mart, is enjoying the fastest growth in sales among the country's leading food retailers, according to data published today (3 March) from TNS Worldpanel.

The UK's second-largest food retailer saw its sales rise 8.8% during the 12 weeks to 22 February, TNS said.

With the recession continuing to weigh on consumer spending, Morrisons enjoyed an 8.2% rise in sales, taking its share of the market to 11.8%.

Ed Garner, director of research at TNS, said shoppers were switching outlets or trading down in-store to search for the lowest prices.

"In the light of this shopper behaviour, Asda's consistent low-price positioning is paying off," Garner said.

Sales at Sainsbury's, meanwhile, rose by 5.7% but below the 6.4% growth seen by the market as a whole. Garner said the retailer's moves to lower prices had led to its sales growth falling behind the market.

"This is explained by self-imposed price deflation as their pricing becomes more aggressive with Switch & Save and the growth of the Basics range," Garner said.

Tesco's sales rose 5%, taking its market share to 30.3%.

Aldi and Lidl continued to enjoy double-digit growth, although Garner pointed to rising sales from frozen-food retailers Iceland and farm Foods, which saw sales rise by 13.6% and 14.7% respectively.

"Freezer centres are enjoying the double benefit of a low-price reputation together with a renaissance in the frozen food category," Garner said.

According to the TNS data, grocery prices rose by 8.7% during the period as the weak sterling continues to drive up commodity prices.