RETAIL sales volumes grew by 0.4 per cent last month, despite Black Friday promotions bringing forward many pre-Christmas purchases into November.

It was the weakest December growth for two years but beat City expectations that the figure would be lower due to the US-imported sales phenomenon shifting shopping patterns.

Year-on-year growth was 4.3 per cent.

The data was skewed by the fact Black Friday sales were included in November's figures for 2014, but were recorded within December's numbers the year before.

But underlying figures comparing sales in the last quarter of the year with the same period in 2013 showed the best growth in a decade, with the five per cent improvement the best since November 2004.

Average prices were 2.2 per cent lower last month compared with December 2013, the largest fall since June 2002, largely as a result of plunging petrol prices.

December's volume growth was driven by supermarket sales and an increase in motorists filling up their tanks thanks to cheaper petrol.

Department stores suffered from the impact of Black Friday as their online sales fell year on year for the first time since records began at the start of 2008.

Month-on-month volumes for these stores fell by 4.5 per cent, the worst decline since January 1996.