FTSE 100 bounces back supported by oil price rise

(Reuters) - Britain's FTSE 100 gained on Wednesday as a 6% rally in energy majors BP and Royal Dutch Shell and positive corporate updates injected calm into equity markets after an oil-driven rout.The commodity-heavy FTSE 100 outperformed its European peers, closing 2.3% higher after cratering oil prices knocked 3% off the index on Tuesday. After falling to its lowest since 1999 earlier in the session, Brent crude prices made up some ground on the prospect of extra pledges from major producers..