It cited an increase in customer traffic driven by lower prices and strong seasonal events.

The figures take into account the early Easter and the effect of the extra leap year day and the increase would have been five per cent with these factors stripped out.

Total sales increased in the "high single digits" for the period up to March 31, the statement added.

Asda outperformed the market for the eighth consecutive quarter with market share up 0.3 per cent year-on-year in the 12 weeks to April 20.

Wal-Mart - which does not give precise figures for Asda - said the company had enjoyed a "healthy" sales performance in April, with strong fresh food sales.

It said that at a time when food commodity prices were on the increase, Asda had continued to lower prices across the weekly shop, maintaining its position as price leader in the supermarket sector.

Mike Duke, Wal-Mart International vice chairman, said: "Asda has continued to win in the United Kingdom – delivering a strong first quarter, with thirty basis points of market share growth, despite a challenging economic environment.

"Although we expect the UK to remain a challenging economy and retail market over the rest of the year, we believe that our strong pricing agenda, backed by a cost reduction programme leaves us well positioned to continue to make market share there."

Asda president and chief executive officer, Andy Bond, added: "Our role to help give customers good quality products at affordable prices is more important than ever before.

"Whilst today's results are encouraging, we mustn't become complacent - especially in the current economic climate.

"We have a duty to lock down inflation by working with our suppliers, to cut costs to ensure that our customers are always getting the best possible deal on their weekly shopping."