London, May 31 - Tesco PLC's share of the U.K. grocery market has risen to 31.3% in the 12 weeks to May 20, according to Taylor Nelson Sofres World Panel market-share data released Thursday.
The figures affirm Tesco's position as the U.K.'s biggest grocer, ahead of rivals Asda and J. Sainsbury (SBRY.LN), which remain at second and third position respectively .
Tesco's share of the market grew from 31.1% a year ago.
Asda's market share in the period grew to 16.7% from 16.4%, while Sainsbury's claimed 16.3%, up from 16.0% a year earlier - both representing growth rates of 8%.
Asda is a subsidiary of the world's biggest retailer Wal-Mart Store Inc. (WMT) of the U.S.
WM Morrison's (MRW.LN) market share, including its Safeway stores, stood at 11.2% for the period, compared with 11.3% a year earlier. However, total Morrison sales in the period grew from GBP2.04 billion to GBP2.15 billion, reflecting a 5% growth rate.
Kwik Save, which this week announced the closure of 79 stores, saw its share of the grocery market slip to 0.2% from 0.8%.
Somerfield fell to 3.8% from 4.2%, a decrease of 4%.
The total grocery market expanded to GBP27.4 billion, up 4%.
TNS Director of Research Edward Garner said the figures would be heartening for Morrison: "Its growth rate continues at the record level of 5% - the highest since the Safeway takeover. This is ahead of any of the new advertising or store revamps coming into action, as recently announced by the retailer."
TNS monitors the household grocery purchasing habits of 20,000 demographically representative households in the U.K.