Life insurance stocks fall back after a dive in UK business sent Prudential's group insurance sales down 9% during the third quarter.The Pru reported insurance sales of £700m for the three months ended 30 September, with nine-month sales also dropping 9% to £2.02bn.UK retail sales slumped 22% to £157m, although they surged 66% in the US to a record £249m, while Asia enjoyed growth of 4% to £293m.Peers Legal & General and Aviva are also nursing substantial losses.The defensive qualities of utility stocks are attracting investors to the sector. Gas supplier Centrica is particularly in demand after saying it has received planning permission for the construction of a wind farm project off the coast of Lincolnshire.Top performing sectors so far todayFood & Drug Retailers 4,601.75 +1.05%Mobile Telecommunications 3,174.05 +0.37%Gas, Water & Multiutilities 3,676.99 +0.35%Fixed Line Telecommunications 1,938.61 +0.13%Bottom performing sectors so far todayLife Insurance 3,767.00 -4.80%Automobiles & Parts 2,557.84 -4.37%Mining 18,031.99 -4.33%Industrial Metals 4,232.15 -4.03%Real Estate 1,962.75 -3.85%