U.K. grocer Sainsbury's says it has experienced a record week of trading during the Christmas period with "excellent" operations across the whole group.
"We think it's a good performance in what of course continues to be a challenging market," Mike Coupe, chief executive officer of Sainsbury's, told CNBC Wednesday.
The second largest U.K. grocer reported an increase in like-for-like sales of 1.1 percent during its third quarter, which includes the Christmas period. Analysts had forecast a 0.9 percent increase, according to Reuters.
A key contributor to these results was Argos, the electricals retailer it acquired in 2016 and now has located within its stores. The number of collections using its fast track service, which allows customers to get their items within four hours of purchasing them, rose by 39 percent and deliveries rose by 25 percent in the three-month period.
Sainsbury's said in a statement that such services "were particularly popular" during Black Friday and the last few days leading up to Christmas.