Boeing forecast on Tuesday that US and Canadian airlines would buy $760 billion worth of new aircraft over the next 20 years, mainly fuel-efficient single-aisle jets. Airlines will buy about 7,350 new aircraft between now and 2030, Boeing said, boosting the regions total fleet -- after counting for retired aircraft -- to 9,330 from the current 6,610. "Barring a prolonged economic downturn, the airline industry is poised for long-term, moderate growth. As a result, we are increasing our demand forecast in the single-aisle category by 330 airplanes," Boeing said in a new report. A lot of the capacity growth will come from increasing demand for services to Central and South America. "The region's airline industry is poised for long-term, moderate growth. Airlines are expected to continue focusing on capacity discipline and improving financial performance," said Randy Tinseth, Boeing Commercial Airplanes vice president. Boeing said long-haul international traffic will grow about 4.5 percent annually, pushing up demand for larger aircraft. In North America, air traffic grew about three percent last year. Worldwide, Boeing expects airlines will buy some 33,500 new aircraft over the next two decades, worth more than $4 trillion.