Sir Peter Davis, CEO of UK supermarket group J Sainsbury, admitted the chain may lose its position as second-largest grocer to Wal-Mart subsidiary Asda.

Taylor Nelson Sofres data puts Asda's share of the UK grocery market in the three months to 15 September only marginally behind Sainsbury's 11.7% at 11%. Trading during the Christmas season tends to favour Asda, as it carries a higher proportion of non-food lines.

Davis is quoted by the Times as saying: "Of course we could be overtaken. But people have been saying that for years. It could happen, but there is no certainty that it will happen."

Analysts are reported to believe that, while Sainsbury could be temporarily knocked off the number two spot over Christmas, Asda could move ahead permanently at some point during 2003.

Same-stores sales at Sainsbury outlets inched up 2.4% during the 16 weeks to 12 October, compared with a 2.7% rise during the previous quarter. The company is expecting to start reaping the benefits of its membership of the new Nectar loyalty card scheme during the coming quarter.

Davis quashed speculation that the group's quarterly dividend would be cut.

Sainsbury has nearly twice as many stores as Asda, but they are on average two thirds the size of Asda's 45,000 sq ft median store size. Sainsbury was once the UK's leading grocer, but slipped behind current leader Tesco in 1995.