J Sainsbury's, Britain's third-largest supermarket chain, beat forecasts for underlying sales in its fourth quarter, helped by growth online and in convenience stores.

The group, which trails market leader Tesco and Wal-Mart's Asda by annual revenue, said that sales at stores open over a year rose 3.6%, excluding fuel, in the 10 weeks to March 16.

That was a 33rd consecutive quarter of underlying sales growth and compared to analysts' average forecast of a rise of 2.3%, and growth of 0.9% in the third quarter.

Total fourth quarter sales rose 6.3%, excluding fuel.

Sainsbury's said it was well positioned to continue to outperform the market in the current year even though it expected the retail environment to remain tough.