Oil prices will rebound rather than extend their decline to as low as $20 a barrel because a collapse since June isn’t merited by global supply and demand, OPEC’s Secretary-General said. Producers outside the Organization of Petroleum Exporting Countries should be first to reduce their output amid a surplus that’s pushed crude below $50 a barrel, Abdalla El-Badri said in an interview with Bloomberg Television at the World Economic Forum in Davos, Switzerland on Wednesday. Iraq, OPEC’s fastest-growing supplier, said it needs to boost output to compensate for revenues eroded by the price slump.