Total food sales at Marks & Spencer (M&S) were up 4.2%, and like-for-like sales were up 1.7% in the in the 13 weeks to 28 June.

The growth offset the decrease in like-for-like sales in non-food products, which were down 1.8% in the quarter.

Marc Bolland, chief executive, said: “Our Food business had another great quarter, continuing to outperform the market through our focus on differentiation through quality and innovation.”

The retailer said it was still on track to open 150 new Simply Food stores in the next three years.

It attributed its specialist strategy, which provided “unrivalled quality and innovation”, for its performance in the food market. In its quarterly trading statement today, M&S also pointed to the success of 700 new products, which have expanded the choice range for customers.

Sales at M& were down 8.1% this quarter, with Bolland stating that the new website had had an “impact on sales”.

The site had intended to transform the 130-year-old business, but customers were forced to re-register and there were reports of navigation problems.