RIYADH: Revenues of aviation hubs in the Middle East could fall by approximately $11 billion by the end of 2021, Airports Council International (ACI) Asia-Pacific said in a statement today. "Consistent with forecasts previously reported in 2020, the Middle East will be one of the hardest-hit regions globally with almost 70 percent passenger losses," it said. In the Asia-Pacific, revenues are forecast to decline by $34 billion, affected by 56 percent passenger losses due to constant lockdowns, stringent travel and quarantine restrictions. The industry"s body has estimated that passenger numbers for the two regions could decline by 2.3 billion by the end of 2021, when compared to pre-pandemic forecasts.