Tesco has suffered a 1.5% decline in total like-for-like sales for the first quarter of 2012, its third consecutive fall.
The results show that Tesco , Britain's biggest retailer, is finding it difficult to implement its recovery plan following January's shock profit warning.
The firm, which accounts for about one in every £10 spent in British shops, said sales at UK stores open over a year - excluding fuel and VAT sales tax - fell 1.5% in the 13 weeks to May 26.
Further afield, it said that first quarter sales for the group, which is the third largest global retailer with over 6,000 stores in 14 countries, rose by 2.2%, including petrol.
"At this early stage of the year, we are performing in line with market expectations for the group," Tesco said in a statement.
"The outlook for the year as a whole remains unchanged."
In January, Tesco stunned the market by issuing a shock profit warning and in March, its UK boss Richard Brasher stepped down after it reported UK trading profits down by 1% to £2.5bn in the year to the end of February.
New chief executive Philip Clarke vowed to turn around the company's fortunes and "put the love back" into the chain after the dip in UK profits.
Tesco's recovery strategy has also involved the closure of its online car sales venture .