Carphone Warehouse's retail arm Best Buy Europe has reported an 8.3 per cent increase in UK like-for-like sales in the 13 weeks to December 27.

But margins and profits have suffered. Overall sales for the quarter rose 13 per cent to just over£1bn. But while like-for-likes across the business were up 6.5 per cent, they were down 1 per cent at constant currency rates and retail gross profit was down 3.7 per cent at constant exchange rates.

The company said the fall in gross profit and margin – which is expected to be down 150 basis points for the full year – was the result of a "deliberately aggressive trading stance to grow market share."

Talk Talk broadband revenues were down 2 per cent.

Reviews of the structure and financial disclosure policy of the company are underway.