Sainsbury’s has admitted disappointing fuel sales and deflation in fuel prices have helped to depress its latest sales results.

The supermarket giant said its retail sales for the 28 weeks to September 27 were down 1.4% to £13.8bn, compared with the same period the previous year, and on a like-for-like basis (excluding new space) sales were down 3.4%.

However, when fuel sales were excluded from the figures retail sales were flat, compared with the same period the previous year, and there was a decline of 2.1% in like-for-like sales.

Sainsbury’s said the difference between the sales figures with and without fuel was “due to retail price deflation in fuel and lower like-for-like fuel volumes”.

The retailer also revealed it will not be going ahead with plans to develop a number of supermarkets after it reported a pre-tax loss of £290m.

The loss was caused by a number of one-off charges totalling £633m, including a charge of £287m because some sites will not be developed.

Despite the cutback in store development Sainsbury’s said it would still open 500,000sq ft of space in each of the next two years, followed by 350,000sq ft in 2017/18. More than half of the new space will be convenience stores as it continues to target opening 100 convenience stores a year.

The company also said it would be investing in lower prices and it was expected this would lead to lower profitability in its next half-yearly results.

Mike Coupe, chief executive said: “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.”