Telecoms were trading with steep losses on Thursday with heavyweights Vodafone, TalkTalk and Carphone Warehouse pulling the sector lower.Vodafone's shares were under pressure, trading 3.2% lower, after Goldman Sachs cut its recommendation for the stock from 'buy' to 'neutral' and reduced its target from 270p to 240p ahead of the company's fourth-quarter results due out next week. UBS kept a 'buy' rating today, but lowered its target from 275p to 255p.The Swiss bank, in particular, expects Vodafone's revenues to fall to £43.9bn in the year ended March, down from £44.4m previously, while operating profits are predicted to slip to £12.9bn from £13.3bn.TalkTalk declined 1.4% after saying that pre-tax annual profit slumped 74.6% to £31m as earnings declined as broadband growth waned.Carphone Warehouse, meanwhile, dropped over 7% as investors gave a cool reaction to its proposed £3.7bn merger with Dixons Retail. The new company, to be named Dixons Carphone plc, is hoped to create a "world-class British retailer for the new digital age", offering consumer electricals, mobiles, connectivity and related services, the firms said on Thursday morning.Others in the mobile telecoms sector including Avanti Communications, Monitise and Inmarsat were also trading in the red. Fixed line telecoms stocks such as BT Group and Telecom Plus were also lower.Top performing sectors so far todayFood & Drug Retailers 3,894.72 +1.49%Pharmaceuticals & Biotechnology 13,159.41 +0.49%Beverages 14,235.81 +0.37%Food Producers & Processors 7,826.60 +0.22%Tobacco 39,701.51 +0.19%Bottom performing sectors so far todayMobile Telecommunications 4,856.24 -2.60%Automobiles & Parts 8,765.41 -2.57%Construction & Materials 4,344.69 -2.54%Technology Hardware & Equipment 1,050.38 -2.54%Fixed Line Telecommunications 4,214.76 -2.53%BC