U.K. retail sales grew more slowly than expected in January after a decline in December 2017, the Office for National Statistics said.

Sales volume edged up 0.1% in January from the month before, with declines across all main sectors except non-food stores.

"Retail sales growth was broadly flat at the beginning of the new year with the longer-term picture showing a continued slowdown in the sector. This can partly be attributed to a background of generally rising prices," Rhian Murphy, senior statistician at the Office for National Statistics, commented.

Annual growth was 1.6%, compared to the 2.4% annual growth in January 2017. Consensus forecasts had been for sales to grow by 0.5% in monthly terms, and by 2.5% year on year.

The pound fell after the release, slipping 0.2% to $1.4066 by 11:11 a.m. in London.

"After what was a particularly tough Christmas trading period for retailers, consumers kept their foot on the brakes throughout January," ING analysts said in a research note.

"Retail sales barely increased in the first month of the year, suggesting shoppers were reluctant to heavily participate in the traditional January sales, backing-up separate findings from Visa. For now, we see few catalysts for a sustained rebound in spending over coming months."

In December, sales had decreased by 1.5% from November, and were up 1.4% year on year.

Growth in the quantity of sporting equipment, games and toys being bought was offset by falling food sales when compared with the same month a year earlier, the ONS said.