In an interim management statement for the 28 weeks to 27 September 2014, the company also unveiled a loss before tax of £290m, compared with a profit of £433m for the same period the year before.
However, Sainsbury’s booked a one-off impairment charge of £628m on the value of its supermarkets and the developments it will no longer build.
New chief executive Mike Coupe said the company’s strategy was “evolving to address the continuing shifts in customer shopping patterns”.
He added: “We have examined every aspect of our business and we have good foundations for future growth in our supermarket and convenience estates, our online and non-food businesses and in Sainsbury’s Bank. However, we need to make sure we are investing in the right areas and, by reducing our costs and capital expenditure, we are ensuring that we have the resources to enable us to do so.
"We will continue to differentiate ourselves from a position of strength by offering great products and services at fair prices, investing in the quality of our food and investing in price in areas where our customers tell us it matters most. By knowing our customers better than anyone else we will continue to serve them through multiple channels and in ways that make their lives easier, regardless of changes in the market. Our colleagues will remain our greatest asset; we will invest in their training and development to ensure they can continue to deliver industry-leading service.”
The company said it would embark on an improvement plan for 3,000 own-brand products – but did not specifically mention bakery. And it pledged to cut prices by investing £150m, of which half will fall on 2014/15 and the remainder in the first half of 2015/16.