Tesco has reported ‘disappointing’ Christmas sales figures, despite a boost in online trading.

Excluding VAT and petrol, sales in the six weeks to January 7 2012 were down 2.3% year-on-year.

The news comes despite Sainsbury’s posting record sales in the 14 weeks to January 8, with like-for-like sales up 2.1%.

Tesco chief executive Philip Clarke said the sales figures were “below our expectations and disappointing, particularly in the context of the difficult weather conditions in 2010.”

But although overall sales were down, online sales revenue increased.

Online sales were strong in both food and non-food with total online sales growth of more than 14%. Approaching one million orders were placed with Tesco Direct during the period, of which over two-thirds were collected in store.”

Sainsbury’s figures were also bolstered by online sales – it reported a 20% jump compared to 2010. Almost 75% of online general merchandise orders at Christmas used ‘Click and Collect’.

And in news that will put pressure on online retailer Ocado, Waitrose said online sales increased nearly 50% over Christmas, contributing to a 3.8% increase in like-for-like sales in December.

In a bid to drive sales Tesco announced its Big Price Drop in September, and also tried to improve the shopper experience.

However Clarke said that the wider improvements in the shopping trip, which are seen as an integral part of strengthening performance, are still to work through fully.

Other high street stores have also posted poor Christmas sales – Argos saw a fall of 8.8% in the 18 weeks to the end of 2011, sales at Homebase dropped 2.6% in the same period, and Mothercare saw a 3% decline in the 13 weeks to January 7.