Retail giant Marks & Spencer is performing well after strong fourth quarter trading statement, providing a boost to the 'general retail' sector. Blue chips Next and Kingfisher are also higher.Peel Hunt upgraded M&S to a 'hold', from 'sell', after results from both general merchandise and food divisions beat expectations.Sector peers Dunelm, Debenhams and Halfords are on the rise on the FTSE 250.The aerospace and defence sector is the worst performing sector today, with Rolls-Royce a notable faller.It was announced today that airline Norwegian has selected the UK engine designer's Trent 100 engines to power nine Boeing 787 Dreamliner aircraft. "This order begins what I firmly believe will be a very strong partnership between Rolls-Royce and Norwegian," said Rolls-Royce's vice president of Customer Business, Dan Pedley. Shares are edging lower.---bcTop performing sectors so far todayGeneral Retailers 1,657.59 +3.75%Banks 4,841.61 +2.59%Life Insurance 4,600.97 +1.46%Industrial Metals & Mining 8,805.35 +1.33%Forestry & Paper 6,538.21 +1.25%Bottom performing sectors so far todayAerospace and Defence 3,370.17 -0.30%Personal Goods 20,151.64 -0.30%Gas, Water & Multiutilities 4,574.83 -0.27%Industrial Transportation 2,575.17 -0.17%Industrial Engineering 7,119.27 -0.11%