Mining stocks are advancing on optimism an improvement in global economic conditions will fuel demand for raw materials. Sentiment was lifted by US Federal Reserve chairman Ben Bernanke who said the world's largest economy had 'very likely' come out of recession.ENRC, Rio Tinto, Xstrata and Lonmin are among the large companies posting good gains.UK Coal is roaring ahead after saying it will raise £100m to give it headroom as it invests in deep mining.Few sectors are in the red, but investors see little utility in defensively-oriented stocks such as the gas supplier Centrica and the electricity group Scottish and Southern. Top performing sectors so far todayBanks 5,178.91 +3.33%Mining 18,233.64 +2.89%Life Insurance 3,717.33 +2.86%Forestry & Paper 3,305.73 +2.81%Real Estate 2,156.47 +2.52%Bottom performing sectors so far todayGas, Water & Multiutilities 3,865.69 -0.67%Electricity 6,669.03 -0.05%Food Producers & Processors 4,447.06 -0.01%