Sainsbury’s market share has dipped to 15.3% from 15.4% during the past 12 weeks to September, according to the latest data from TNS Superpanel.

This compares to a 15.9% market share for the same period last year. TNS also indicated that sales at Sainsbury were flat year-on-year in the latest 12-week period, compared with a 9% rise for Tesco.

Tesco, which accounts for 28% of UK grocery spending, is seeing faster growth than its rival Asda, which accounts for 16.8% of the market.

Safeway’s market share has also dipped in the last month and is now just 6.9%, down from 8.8% a year ago. This indicates the impact of the Morrisons’ store rebranding programme whereby three Safeway outlets are being revamped and reopened every week.

Morrisons continues to gain market share as it converts the Safeway stores to its own branding, and the TNS data shows its market share in the 12 weeks to September 12 at 6.7% compared to 5.8% in the same period last year.