A strong Christmas trading update from Tesco has given the food retail sector a lift. The supermarket giant said it enjoyed its best Christmas in three years as shoppers braved the winter weather to stock up on festive treats.In the six weeks to January 9, the firm posted a 5.1% year-on-year rise in like-for-like sales excluding petrol and VAT at its UK business, ahead of expectations. Champagne sales rose by 35% with the 'Finest' range also performing well, Tesco said. Peers Sainsbury's and Morrisons are also higher.Among today's sectors in the red is technology hardware and equipment, despite good gains from Satnav group Trafficmaster, which says it traded well towards the end of the year.Top performing sectors so far todayHealth Care Equipment & Services 3,582.81 +0.84%Fixed Line Telecommunications 2,051.93 +0.82%Life Insurance 3,970.12 +0.80%Food & Drug Retailers 4,769.11 +0.34%Automobiles & Parts 2,910.89 +0.16%Bottom performing sectors so far todayForestry & Paper 3,845.37 -4.42%Industrial Metals 5,138.37 -3.61%Industrial Transportation 2,069.87 -3.15%Mining 22,600.43 -2.80%Technology Hardware & Equipment 374.94 -2.28%