Sainsbury’s was the only supermarket out of the big four to increase its market share in the run up to Christmas, according to the latest data from Kantar Worldpanel.

Contrary to analyst reports last week suggesting Sainsbury’s could have struggled over the crucial festive period, Sainsbury’s market share edged up from 17% to 17.1% in the 12 weeks to 23 December 2012. Its sales growth was 3.4%. The chain is due to release its third-quarter figures tomorrow (9 January).

Tesco also put in a much improved performance during the period. Although it lost market share, from 30.6% to 30.5%, Kantar said the dip was better than the rest of 2012 when its average share drop was 0.4%. It notched up sales growth of 2.9%.

Waitrose and the discounters continued their impressive run. Waitrose, Aldi, Lidl and Iceland all increased their market share, and Aldi and Lidl’s sales growth was in double digits.

“Historically, the discount sector has seen its share dip at Christmas as shoppers treat themselves and trade up, but the all-time record share of 3.2% at Aldi is a sign of the times and shows that this is no longer the case,” said Kantar Worldpanel director Edward Garner.

The Co-op also recorded sales growth of 0.1% - the first positive sales growth for some time. But Morrisons sales fell 0.6% and its market share dropped from 12.4% to 12% during the period. Yesterday (7 January), it reported a 2.5% drop in like-for-like sales in the six weeks to 30 December.