Shares in the world’s biggest energy groups have tumbled in a market rout as plunging oil prices put at risk billions of dollars of investment and jeopardised future supplies of crude. The sharp slide in the price of Brent oil after Opec’s decision not to cut output triggered warnings that oil companies would cut as much as $100bn of capital spending in response, imperilling the US shale bonanza and threatening much Arctic oil exploration. Meanwhile oil’s fall continued to play havoc with the currencies of oil exporting countries, especially Russia. At one point on Friday, the rouble slid to a record low. More On this story On this topic IN UK Equities Leonid Fedun, vice-president of Lukoil, Russia’s second largest crude producer, told the Financial Times that Opec was trying to turn the US shale oil “boom” into a “bust” for smaller producers. He compared the surge in North […]