New York: US policymakers should gradually lift the country’s decades-old ban on crude oil exports because allowing the shipments would make the global energy system and fuel prices more stable, the head of Royal Dutch Shell Plc said on Tuesday. “Policymakers here in the United States should embrace a truly liberalised, diverse and global energy market,” Shell Chief Executive Officer Ben van Beurden told an energy conference at Columbia University in New York. US oil and natural gas exports “would reinforce the long-term future of North American energy production,” significantly improve the US balance of trade, and “help to make the global energy system much more stable,” he said. The United States has banned most crude exports since the Arab oil embargo of the 1970s. But pressure on the Obama administration and on Congress to overturn the restriction has risen amid the domestic shale energy boom of the last several years.