London's top stocks are expected to start around 13 points lower, with investors likely to focus on figures from retailers Tesco and Game.Supermarket giant Tesco saw strong sales in the third quarter as its Clubcard reward scheme helped it draw in customers and it continued to benefit from increasing non-food sales. UK like-for-like sales excluding petrol and VAT were up by 2.8%, in line with analyst expectations. New stores in the UK contributed 2.9% to growth, bringing total sales growth excluding petrol to 5.7%.Video game retailer Game said it approaches the key Christmas shopping season cautiously and has seen softer than expected sales of some software releases, but added that it is well positioned to deliver a solid outturn for the year. The group also reiterated its gross margin guidance for an increase of between 170 to 220 basis points over the prior year. Mining giant Xstrata is to take charges of nearly $2.5bn this year after restructuring its copper, zinc and nickel operations in Canada and Australia. In Canada, it will take a $375m charge for the permanent closure of its copper and zinc metallurgical plants at the Kidd Metallurgical site in Timmins next May, which is part of a plan to restructure its Canadian metallurgical operations. Kosmos Energy, Tullow Oil's operating partner on the West Cape Three Points Block, offshore Ghana, has reported another encouraging test drilling.Plastics group Victrex saw profits slide in the year to 30 September as demand slumped but said it had successfully cut costs while maintaining growth prospects, leaving it well placed to benefit from the upturn. Domino Printing revealed an 11% increase in annual pre-tax profit and raised its dividend after a series of cost cutting measures.