The number of retailers reporting falling sales rose to its highest level in almost 13 years in the past 12 months, a survey shows.

Forty-six per cent of retailers said their sales fell in the year to April against 32 per cent who reported rising sales, according to the monthly Distributive Trades Survey by business lobby group the CBI.

The balance of minus 14 per cent was the biggest year-on- year fall since July 1992, when it hit minus 15 per cent. The April figure also compared unfavourably with the balance in March of minus nine per cent.

CBI chief economic advisor Ian McCafferty said tough trading conditions were continuing for most retailers despite expectations last month that the position would stabilise.

The ongoing decline in sales was likely to reflect the recent fall in real disposable incomes, higher fuel and utility bills, reduced housing market activity and higher mortgage rates than a year ago, he said.

"These results add further weight to the argument against a premature rise in interest rates," Mr McCafferty said.

There was poor trading in most sectors during the period, particularly by chemists and furniture and carpet retailers, the survey showed.

However, household durable products did relatively well, probably due to sales of technology products such as I-Pods and DVDs. Booksellers, stationers and grocers were the only others among 11 sectors to grow sales.