London's blue-chips have opened firmer with resources stocks in demand and a solid update from Tesco providing some encouragement for buyers.Miners and oil stocks lead the risers with the price of crude edging up towards the $90 per barrel mark. Essar, Fresnillo and Antofagasta are the best of the risers. On the downside, banks are under pressure ahead of the Irish budget and continuing talk at the EU finance ministers' meeting of 'haircuts' for bondholders in distressed countries. Barclays, Lloyds and Royal Bank of Scotland are all lower. Good momentum across at its whole business helped supermarket giant Tesco lift sales by 8.8% in the past three months, though its international businesses again led the way. The UK also picked up towards the end of the quarter.Plumbing supplies firm Wolseley said its first quarter trading performance was slightly ahead of expectations. Revenue in the three months ended 31 October rose 2% to £3,471m from £3,395m the year before. Like for like sales grew 4%.Engine producer Rolls-Royce has made its second contract win announcement of the week, this time it's a £20m deal to provide the design, propulsion systems and deck machinery for four deep water platform supply vessels.Standard Life has agreed to buy pensions and life product back office software group Focus Solutions through a £42m, 140p per share, all cash offer. Housebuilder Bellway expects net interim profits this year will be up by 20% on last year as buyer interest has picked up a little since the government's comperehensive spending review. Reservations are now ahead of the board's expectations, although still slightly down compared with the same period last year, while the decline in consumer confidence appears to have levelled out, it says.