The oil-services sector was out of favour on Tuesday, pulling back after a sharp rise the day before, as disappointing results from blue-chip firm Wood Group dampened sentiment.Wood Group, one of the largest companies in the sector with a market capitalisation of around £3.4bn (as of yesterday's closing price), slumped by as much as 10% today after the company scaled back its outlook for its engineering division.The company now expects full-year EBITDA growth at Wood Group Engineering to be between 10% and 15%, below its earlier guidance of 15%, reflecting some project delays and further weakening in Canada.Nevertheless, on the group level the company reported good growth in the first half, with revenue up 3.0% at $3.5bn and EBITDA up 18.6% at $243m. The firm said it still expects to deliver full-year results in line with expectations.By 15:26, the stock was down 8.03% at 830.5p, its lowest level in last seven weeks.Stocks in the sector rose strongly on Monday on hopes that two rejected takeover approaches for engineering solutions group Kentz Corporation would spark a bidding war and drive M&A activity across the sector. After a +20% share-price rise yesterday, Kentz was pulling back slightly today.AMEC, one of the firms whose offer was rebuffed by Kentz, was also trading lower. Credit Suisse said in a research report this morning that while a "competitive bidding war could evolve [...] we would be surprised if AMEC chose to participate".Sector peers Hunting and Petrofac were both lower today.Top performing sectors so far todayIndustrial Transportation 2,958.23 +0.98%Fixed Line Telecommunications 3,733.29 +0.84%Gas, Water & Multiutilities 5,703.02 +0.56%Pharmaceuticals & Biotechnology 11,228.85 +0.43%Mobile Telecommunications 4,447.60 +0.28%Bottom performing sectors so far todayIndustrial Metals & Mining 1,408.18 -4.90%Oil Equipment, Services & Distribution 23,350.73 -3.28%Construction & Materials 3,849.35 -2.13%Life Insurance 6,195.48 -2.12%Automobiles & Parts 7,778.75 -2.06%BC