UK supermarket chain Sainsbury's has posted a 0.2% slide in second-quarter like-for-like sales as it failed to take advantage of the hot summer weather, which boosted sales at other retailers, including Tesco and Morrisons.

Group chief executive Peter Davis attributed the poor performance to disruption due to its business transformation programme, which involves new IT infrastructure, new supply chain and modernised stores.

"Sales are being disrupted as we build solid foundations for future growth. Our trading in this quarter has been similar to that of quarter one. While we are not satisfied with our current sales performance our first priority is to complete the programme. We have also had to restrict flexibility while implementing new systems," Davis said, adding that the company expects to compete the programme by March 2004.

Davis said that in the short term, Sainsbury's had improved its customer service and had achieved record mystery shopper scores. The chain plans to take on an extra 10,000 staff for the busy Christmas period.

At the group's US supermarket business, Shaw's, total sales rose 2.6% in the second quarter, while like-for-like sales rose 0.4%.

The company's sales figures for its second quarter to 11 October are based on the actual results for 15 weeks and estimates for the last week and include petrol.