Keller is among the stocks dragging the construction and materials sector lower. The ground engineering specialist Keller suffered a 34% slump in profits in 2009 and is yet to see any sustained upturn in orders, it said today. Commercial construction in the developed world is likely to contract further, particularly in the US, which Keller says will increase the downward pressure on margins.There was more gloom for the sector from building materials maker CRH, which revealed a 55% drop in full year pre-tax profit and expects a difficult demand backdrop through much of 2010.Among the sectors in the blue is technology hardware & equipment. Pace gave the sector something to be cheerful about when the set-top box maker posted a sharp rise in profits amid continuing strong demand for new TV technologies such as HD and 3D.Top performing sectors so far todayBanks 4,807.43 +1.61%Technology Hardware & Equipment 398.31 +1.45%Forestry & Paper 4,256.84 +1.36%Mobile Telecommunications 3,334.00 +0.81%Travel & Leisure 4,458.18 +0.69%Bottom performing sectors so far todayLife Insurance 3,469.94 -2.12%Insurance (non-life) 1,375.45 -0.73%Industrial Metals 5,558.05 -0.71%Industrial Transportation 1,996.97 -0.63%Construction & Materials 3,509.57 -0.54%