Asda, unlike Tesco and Asda, increased its number of promotions in December, according to data from just-food's Promo Tracker.

The UK's second-largest grocer, perceived by some industry watchers to have "won" the battle among the country's largest food retailers over the festive period, had 23.6% of its SKUs on offer last month, the Tracker said. In November, 22.5% of products at Asda were sold at a discount.

Asda was alone in the four retailers monitored by the Tracker - which is compiled in association with mysupermarket-insights.co.cuk - to have upped their promotions in December.

At Tesco, 36% of SKUs were on offer, compared to 40.3% the month before. In Sainsbury's stores, 37% of lines were on promotion, against 38.6% in November. Ocado had 27.9% of its products at a discount in December versus 31.6% the month before.

However, the average saving per promotion at Asda, Sainsbury's and Ocado all increased in December.

On Monday, analysts at Shore Capital, citing data from Nielsen, said Asda "appeared to be the winner" of the Big Four retailers in the four weeks to Christmas. Asda sales climbed 10.7%, according to Nielsen, although sales were boosted by the integration of Netto's UK stores into its network.

Nonetheless, Shore Capital said: "Shore Capital had expected Asda to be crowned 'Big Four Christmas kings 2011', benefiting from what we deem to be very effectively converted Netto stores, favourable comparatives it has to be said, and good execution, particularly the blend of advertising, promotions, vouchers and offers."

The Promo Tracker, meanwhile, showed that, for the second month running, 100% of Ocado's Reflets de France and Danone's Actimel SKUs were sold on promotion. Muller was the third-most promoted brand. Rice brand Tilda was fourth on the list, with over 81% of its SKUs on offer, its highest level of the year. Fifth was a second Danone brand, Activia.

Supermarket Total number of SKUs Number of Promos % of all SKUs on promo Average saving per promo
Tesco 37657 13572 36.04 £0.85
Asda 31137 7358 23.63 £0.71
Sainsbury's 24847 9197 37.01 £1.19
Ocado 18690 5220 27.93 £1.2
Brand PcntOfPromos AvgSavingPerPromo
Reflets de France 100 £0.33
Actimel 100 £0.71
Muller 85.1 £0.37
Tilda 81.4 £0.67
Activia 79.8 £0.27
Kettle 76.8 £0.56
New Covent Garden Food Co. 75.3 £0.61
Quaker 74.5 £0.37
Häagen-Dazs 73.2 £1.15
Pringles 71.2 £1.03
Campbell's (Soup & Mixes) 70.5 £0.31
Green & Black's 69.4 £0.85
Lindt 68.3 £0.92
KP 68.3 £0.72
Colman's 67 £0.34
Walkers (Crisps, Snacks & Dips) 66.1 £0.5
Fox's (Biscuits) 65.9 £1.27
Bassett's 65.6 £1.29
Ben & Jerry's 62.7 £1.36
Whitworths 61.5 £0.25
Category PcntOfPromos AvgSavingPerPromo
Crisps 56.34 £0.57
Boxed Chocolates 55.53 £1.41
Yogurts 53.66 £0.29
Frozen Pizza & Breads 53.39 £0.57
Frozen Vegetarian 50.42 £0.46
Chilled Desserts 49.6 £0.33
Baby Food & Snacks 49.27 £0.22
Cider & Alcopops 47.07 £0.88
Cooked, Prepared Meat & Poultry 46.55 £0.57
Yogurt & Milk Drinks 46.13 £0.51
Stock, Sauce Mix & Gravy 46.1 £0.28
Snack Meals 44.61 £0.18
Fresh Soup 44.51 £0.54
Fresh Vegetarian Food 43.31 £0.7
Frozen Desserts & Fruit 40.8 £0.52
Packet Soup 40.71 £0.27
Block Chocolate 40.17 £0.55
Frozen Ready Meals 38.84 £0.43
Tinned Pasta 38.12 £0.13
Snacks 37.59 £0.46