Debenhams, the UK retailer, posted record December sales as better promotions and a surge in online shopping lifted turnover at Britain's second-largest department store chain.

Sales for the 18 weeks ending on 5 January rose 2.9 percent, the company said in a statement published Tuesday on its website. December sales, which the company records during the five weeks prior to 5 January, rose 5 percent to a company record. Online trading, the group said, surged 39 percent over the full 18-week period.

"The trading environment was extremely challenging but we focused on meeting the needs of our customers and executing the four pillars of our strategy," said Debenhams CEO Michale Sharp. "We continue to believe that whilst consumers have become acclimatised to the new economic reality, we don't anticipate a significant change in consumer confidence in the remainder of the year.

"We remain committed to prudent investment in key areas of the business to deliver long-term sustainable growth as well as driving shareholder value."

The company said it expects to see an improvement of around 0.1 percent in its overall gross margin, around half of what it had originally forecast, thanks to the increased costs associated with its promotional drive.

Sharp told a conference call of investors and media members that this year's Christmas trading season was the most competitive he has seen during his 37-year career in retail.

The British Retail Consortium said Tuesday that like-for-like sales across the country in December rose a modest 0.3 percent last month, with the lobby group describing the Christmas sales season as "underwhelming" owing to muted consumer confidence and an overall lack of optimism from British shoppers.

Online sales, however, remained the bright spot for UK retailers, rising 20 percent last month, the BRC said, from an annual monthly average of around 12 percent.

The accountancy and consulting group BDP LLP said Monday that like-for-like sales increased by 1.9 percent for Britain's larger retailers in the five weeks that ended on 29 December, thanks to a wave of online shopping and bargain hunting.

The group's annual High Street Sales Tracker said online sales surged 30.9 percent from the same period last year, while footfall on the weekend before Christmas was up 22 percent.

Debenhams shares fell 3.2 percent in the opening minutes of London trading to change hands at 113.7 pence each in London. The shares have risen more than 88.8 percent over the past year.