Oil titan ExxonMobil could be about to go on a shopping spree, according to rumours doing the rounds. BP, off 5¼p at 526¾p, was thought to be the likely candidate, but BG, 10½p lower at 990½p also got a mention. Speculation was sparked by a Bernstein note, pointing out that Exxon has cash to splash and could hoover up rivals looking cheap.