Drugs and utilities stocks were among the few making gains on Tuesday afternoon, as investors sought 'safer', more defensive assets on the back of some gloomy employment data out from the US on Friday.GlaxoSmithKline and AstraZeneca were providing a lift in the pharmaceuticals and biotechnology sector, while Severn Trent, United Utilities and National Grid were boosting the gas, water and multiutlities sector.In contrast, oil equipment, services and distribution stocks were widely sold off with FTSE 100 oilfield services outfit Petrofac down over 4% after Liberum Capital downgraded the stock from buy to hold.Meanwhile, oil and gas engineering peers Wood Group and AMEC were also heavy fallers despite the Financial Times yesterday highlighting the two businesses as potential beneficiaries of the upcoming decommissioning of North Sea infrastructure in the coming years. The paper cited Neil Bruce, Chief Operating Officer of AMEC, as saying that the market for decommissioning platforms in the region is "huge". "There are more than 500 fixed installations in production and the eventual cost to decommission them and all the other facilities over the next 30 or so years could be in the many tens of billions of pounds," he said.Penny stock Rock Solid Images was a big mover, dropping over 40% after it said on Thursday that it had signed agreements in relation to a $1m credit facility with two of its largest shareholders. The drilling consulting firm had been hit by operational delays in processing client data in January and February which required it to strengthen its working capital base, the company said.Top performing sectors so far todayPharmaceuticals & Biotechnology 9,686.40 +0.86%Gas, Water & Multiutilities 4,894.84 +0.75%Construction & Materials 3,394.11 +0.16%Electricity 8,371.28 +0.16%Mobile Telecommunications 3,983.48 +0.11%Bottom performing sectors so far todayOil Equipment, Services & Distribution 25,786.17 -3.42%Automobiles & Parts 4,533.51 -2.95%Industrial Metals & Mining 3,869.82 -2.80%Mining 19,712.22 -2.11%Industrial Engineering 7,438.00 -2.04%BC