The UK's top three retailers all gained market share in the latest period, but Wm Morrison continued to fall, partly due to store disposals, according to the latest data from TNS Superpanel.

For the 12 weeks ending 14 August 2005, Tesco edged forward to a market share of 30.5%, just ahead of its 30.4% share last period but dramatically ahead of 28.1% seen a year ago.

Sainsbury held on to its recently improved trend, lifting its share from 15.4% a year ago to 15.7% in the current period. Asda meanwhile continued its turnaround from recent declines with a second successive period of gains. The Wal-Mart subsidiary's market share in the latest period was 16.7%, up from 16.6% a year ago.

Edward Garner, communications director of TNS Superpanel, said competition in the grocery market remains as fierce as ever.

The combined share for Morrisons/Safeway continued to fall sharply, mainly due to 196 store disposals.

"The store conversion programme should be completed by the year-end by which time Safeway will cease to exist and we should have a clearer measure of the final size of the Morrison's operation," Garner said.

Store conversions within the Somerfield group are reflected in the growth of the Somerfield fascia and the decline of Kwik Save but the combined share for the group grew from 5.7% a year ago to 5.9% in the latest period.