Online grocer Ocado enjoyed a late surge in sales in the last week before Christmas, up 23.8% on the previous year.

Orders were up 21.8% from 2010 at 450,700 in the four-weeks to Christmas. Gross sales increased 16% to £59m in the same period.

In the 16 weeks to November 27 gross sales increased 10.8% to £198.2m. Average orders per week in the quarter increased 13.5% to 113,200.

Chief executive Tim Steiner said the absence of snow in 2011 allowed Ocado to release additional delivery slots to customers in the days leading up to Christmas.

The business said 97% of orders were on time or early compared to 94% in 2010 despite having previously suffered capacity problems at its distribution centre two months ago.

Steiner said: “Looking ahead, we remain focused on delivering growth in orders at our Hatfield warehouse.”

Chief financial officer Andrew Bracey said: “This was encouraging trading for December as a whole and particularly the seven days to Christmas.”

Bracey added: “In giving guidance for the quarter, we have taken account of likely customer behaviour against the backdrop of the prevailing economic conditions and forecasts; we remain optimistic about continued sales growth and believe Ocado will remain a strong performer in the sector.”