Stocks in the oil sector were the best performers on Thursday as crude prices rebounded from a seven-month low.Before the close in London, Brent futures were up $0.93 at $106.55 on the InterContinental Exchange as the P5+1 group of world powers - China, France, Germany, Russia, UK and US - continued to argue with Iran over its nuclear programme. Oil and gas E&P peers BP and BG Group were among the best performers, both gaining around 3%; oil services firm Amec was also wanted.Royal Dutch Shell was on the up after extending the offer deadline for AIM-listed Cove Energy after its previously recommended offer was trumped by Thai firm PTT Exploration and Production (PTTEP) on Wednesday. Top performing sectors so far todayOil Equipment, Services & Distribution 23,458.50 +3.03%Oil & Gas Producers 7,631.06 +2.92%Life Insurance 3,867.42 +2.70%Banks 3,451.91 +2.45%Industrial Transportation 2,267.13 +1.95%Bottom performing sectors so far todayIndustrial Metals & Mining 3,082.53 -0.49%Automobiles & Parts 4,288.01 -0.38%Personal Goods 21,079.06 -0.14%BC