The world risks becoming ever more reliant on Middle Eastern oil as lower prices derail efforts by governments to curb demand, the west’s leading energy body has warned. The head of the International Energy Agency told the Financial Times that Middle Eastern producers, such as Saudi Arabia and Iraq, now have the biggest share of world oil markets since the Arab fuel embargo of the 1970s. Demand for their crude has surged amid a collapse in oil prices over the past two years that has cut output from higher-cost producers such as the US, Canada and Brazil.