Department stores and smaller shops lifted U.K. retail sales more than economists expected over the Christmas season.

Sales increased 2.6 percent from November, including fuel, the U.K. Office for National Statistics said Friday, strengthening the pound. That percentage rise is the strongest in December since records began in 1996, and matches only one previous monthly increase recorded in February 2010. Twenty-two economists polled by Bloomberg News forecast only a median 0.3 percent gain. Department stores reported an 8.7 percent increase in sales.

U.K. retail sales fell 0.9 percent in October and grew very slightly in November.

From December 2012 to December 2013, retail sales grew 5.3 percent, the most in nine years. Online sales accounted for 11.8 percent of total retail sales in December, up from 10.9 percent last year.

Excluding fuel sales, retail sales rose 6.1 percent in December from a year earlier and 2.8 percent from November.

Sales at large stores rose 2.6 percent from a year earlier, while sales at smaller stores (with less than 100 employees) rose 8.1 percent, according to the Office of National Statistics.