Tesco's shares surged nearly 14% after it said it would cut costs substantially next year, close 43 unprofitable stores and lower prices, as chief executive Dave Lewis attempts to turn around the struggling supermarket chain. The news came as the company unveiled a "broad-based improvement" in UK trading with the like-for-like (LFL) sales decline easing to just 0.3% over Christmas. Rival chain J Sainsbury was also boosted by reform strategy, after announcing plans to cut the price of 700 products this week in order to stay competitive. The company has now invested £150m to lower the prices of over 1,000 products in response to falling sales figures. Rival Morrison's shares also rallied significantly.Retailer Marks & Spencer's shares fell after sales of general merchandise and womenswear over the Christmas period were significantly worse than had been expected, falling 5.8% on a LFL basis.Taylor Wimpey was among the fallers after Credit Suisse cut its target price for the shares, saying that valuations across the housebuilding sector are too expensive.Easyjet and International Consolidated Airlines Group both fell as oil prices stabilised after a recent collapse. Airline stocks have performed well recently on the back of hopes for lower fuel costs. RisersTesco (TSCO) 206.65p +13.54%Sainsbury (J) (SBRY) 249.00p +8.45%Morrison (Wm) Supermarkets (MRW) 183.20p +6.88%Vodafone Group (VOD) 223.75p +3.59%Intertek Group (ITRK) 2,388.00p +3.42%SABMiller (SAB) 3,331.00p +3.05%Aviva (AV.) 477.20p +3.00%GlaxoSmithKline (GSK) 1,420.00p +2.97%Friends Life Group Limited (FLG) 361.40p +2.96%Antofagasta (ANTO) 740.50p +2.92% FallersMarks & Spencer Group (MKS) 444.00p -4.15%International Consolidated Airlines Group SA (CDI) (IAG) 474.30p -1.43%easyJet (EZJ) 1,624.00p -1.22%Weir Group (WEIR) 1,749.00p -0.91%British Land Co (BLND) 772.00p -0.90%SSE (SSE) 1,592.00p -0.50%TUI AG Reg Shs (Post- 16/12/14)(DI) (TUIJ) 1,077.00p -0.37%Barratt Developments (BDEV) 452.30p -0.24%Taylor Wimpey (TW.) 132.10p -0.23%Land Securities Group (LAND) 1,171.00p -0.17%