British supermarket group Sainsbury's has today reported a third consecutive quarter of declining underlying sales, hurt by weak clothing and general merchandise markets. 

The group had its £7.3 billion takeover of rival Asda blocked by the UK competition regulator in April.

It said today that its like-for-like sales, excluding fuel, fell 1.6% in the 16 weeks to June 29, its fiscal first quarter. 

The outcome compares with analysts' forecasts in a range of down 1.1% to down 2% and a fall of 0.9% in the previous quarter. 

"Retail markets remain highly competitive and promotional and the consumer outlook continues to be uncertain," Sainsbury's said. 

The group said while total grocery sales fell 0.5%, general merchandise sales declined 3.1% and clothing sales were down 4.5%. 

Despite the sales falls, Sainsbury's said it gained market share in key general merchandise categories and in clothing, where it is now the UK's fifth largest retailer by volume. 

Recent official data and updates from peers, including market leader Tesco, had already outlined a difficult backdrop for retailers in the period.

This reflected ongoing political uncertainty and a tough comparison with the same quarter last year when the UK enjoyed record hot weather and major events including a royal wedding and the men's soccer World Cup. 

With Sainsbury's shares down 37% over the last year, chief executive Mike Coupe is under pressure to show the group can prosper on its own after the Asda debacle.

He will face investors tomorrow at the group's annual shareholders' meeting. 

In May he vowed to improve stores, cut prices on daily essentials and invest in online to restore sales growth. 

Since February Sainsbury's has reduced prices on over 1,000 own brand products including dairy, meat, fish, poultry and fresh fruit and vegetables. 

Before today's update analysts were forecasting that profits would go backwards in Sainsbury's 2019-20 year. 

The pretax profit consensus was £632m, down from the £635m made in 2018-19.