Retailers weathered toughening high street conditions to post a sales rise in September, but the slower rate of growth experienced since May continued.

The CBI’s Distributive Trades Survey revealed that 37 per cent of retailers increased sales while 25 per cent suffered a decline. The positive balance of 12 per cent was below the 17 per cent expected before the credit crunch turmoil and was the lowest balance reported this year.

Booksellers suffered a sharp reversal of fortunes in the wake of July’s Harry Potter effect. The sector’s balance of -77 per cent was the weakest in the 23-year history of the survey.

Clothing sales fell for the fourth month in a row and the balance was -16 per cent, although sales of shoes rose.

Home improvement – in particular furniture and carpets and hardware and DIY – all recorded rises.

Store groups hope for higher sales growth next month. However, although 12 per cent of retailers expected good volumes, 21 per cent forecast them to be poor.

Asda executive director John Longworth, chairman of the CBI’s Distributive Trades Panel, said: “Retailers will be relieved to see that the recent troubles on the financial markets didn’t have a serious impact on consumer spending in September.

“However, four consecutive months of more modest spending growth prove that higher interest rates are continuing to have an effect.”