Asda has upped its share of the UK grocery market, according to the latest figures from TNS Worldpanel.

The Wal-Mart arm lifted its share of UK grocery sales from 16.9% to 17.2% during the 12 weeks to 23 March, TNS said.

Morrisons retained its 11.6% share of the market but Sainsbury’s and Tesco suffered small share losses, despite posting rising sales.

Sainsbury’s share reached 16.2%, TNS said, while Tesco, the market leader, accounted for 31% of grocery sales.

As a whole, UK grocery sales increased by 7%, thanks to an early Easter and food price inflation.

However, Edward Garner, director of research at TNS, warned that these figures could be distorted by seasonal factors. “This market growth should be treated with caution – next period will be better compare like with like,” he said.