FTSE slides on oil

BP fell 1.48% to 664.50p, Shell dropped 0.42% to 1,886p and BG declined 0.41% to 725.50p after Goldman Sachs cut estimates across the sector and May crude drifted back 74 cents a barrel to $66 in US trade. GlaxoSmithKline fell 1.51% to 1,500p after it was downgraded to "neutral" from "buy" at UBS following disappointing results for Advair. Tate & Lyle also dropped 1.91% to 564.50p as a consumer advocates group in the US suggested its Splenda sweetener could cause digestion problems. Meanwhile, Severn Trent gained 6.31% to 1,197p after it announced it is to demerge its Biffa waste-d...