Dixons Retail said sales declines accelerated over the key Christmas period, though the firm maintained gross margins and claimed it outperformed competitors in Britain.
The electricals chain, home to Currys and PC World in Britain, said group sales at stores open over a year fell five per cent in the 12 weeks to 7 January.
That compares to analyst forecasts of a fall of 4-6 per cent and a decrease of three per cent in the second quarter.
Dixons, which also runs Elkjop in Nordic countries, UniEuro in Italy and Kotsovolos in Greece, said gross margins across the group were flat year on year.
The firm said the sale period after Christmas was distorted by the UK's VAT sales tax rise last year.
Like-for-like sales in the two weeks to 14 January were up two per cent.
"Consumer confidence in many of our markets remains fragile and we will maintain a cautious approach to the outlook for the year ahead," said chief executive John Browett.
European shoppers have been curbing spending as their disposable incomes are squeezed by rising prices, muted wages growth, government austerity measures and fears over the impact of the euro zone debt crisis.