Underwhelming results from sector giants, AMEC and Hunting, meant that the oil equipment, services and distribution sector was the worst performing sector on Thursday afternoon.FTSE 100 firm AMEC, which provides engineering and project management services to the oil and gas markets, fell nearly 4.75% to 872p by 15:57 despite revenues rising by 4% from £1.43bn to £1.48bn in the first half. A strong performance in its mining and power and process divisions - and increased activity in the UK North Sea - more than offset the anticipated reduction in activity levels within the oil sands and federal businesses of AMEC in the six-month period.FTSE 250 energy service group Hunting was also out of favour even though it nearly doubled its pre-tax profits in the half year to 30 June on the back of surging oil prices. Shares fell 3.2%.Meanwhile, the beverages sector was making gains helped by FTSE 100 drinks giant Diageo.The firm, famous for its Guiness-branded stout, posted a 2% increase in sales in the year ended 30 June, as strong growth in the emerging markets outweighed more subdued conditions in Europe. Shares jumped 4.11% to 1,164p. Nichols, the Vimto maker, was also in demand, gaining 0.6%.BCTop performing sectors so far todayIndustrial Metals & Mining 5,525.51 +2.69%Industrial Transportation 2,110.91 +1.55%Automobiles & Parts 4,346.46 +1.31%Forestry & Paper 5,461.08 +1.30%Beverages 8,994.49 +0.95%Bottom performing sectors so far todayOil Equipment, Services & Distribution 19,996.03 -3.71%Mobile Telecommunications 3,686.37 -3.23%Food & Drug Retailers 4,287.94 -2.97%Insurance (non-life) 1,352.66 -2.71%Life Insurance 3,615.67 -2.70%