The industrial metals and mining sector is the worst performing sector today, led lower by Finnish miner Talvivaara.The company lowered annual production guidance to take into account longer than previously anticipated maintenance breaks, and believes it realistic to anticipate a production shortfall of 5,000-8,000 tons of nickel from the previous guidance. Full year production guidance for 2011 has been revised down to 22,000-28,000 tons of nickel. The banking sector is making ground today.The lenders are firmer in London after the Bank of England resisted calls to raise interest rates. The benchmark rate is unchanged at a record low of 0.5% and the quantitative easing programme has been maintained at £200bn. Blue chips HSBC, RBS, Barclays, Lloyds and Standard Chartered are among the best performers. Top performing sectors so far todayBanks 4,880.63 +1.27%Pharmaceuticals & Biotechnology 8,871.64 +0.69%Mobile Telecommunications 4,086.61 +0.67%Life Insurance 4,603.72 +0.31%Food & Drug Retailers 4,628.96 +0.23%Bottom performing sectors so far todayIndustrial Metals & Mining 8,438.66 -3.96%Automobiles & Parts 4,727.57 -3.35%General Retailers 1,618.98 -1.72%Electronic & Electrical Equipment 2,985.31 -1.62%Industrial Engineering 7,001.16 -1.43%