By Julie Johnsson

Bloomberg News

CHICAGO — Boeing Co. predicts demand in Asia will push commercial aircraft sales to $5.2 trillion over the next 20 years, as China overtakes the United States as the world’s largest aviation market.

Boeing, which makes more planes than anyone else, is projecting 4.2 percent more jetliner sales than it did in last year’s forecast even with global shocks that periodically restrain transactions, said Randy Tinseth, vice president of marketing at Boeing’s commercial airplane unit. The outlook helps steer Boeing’s long-range planning for aircraft production.

China’s emergence as an aviation superpower will help drive the market expansion, as will airlines’ quest for more efficient aircraft and continued growth in the budget carrier sector, Tinseth said.

Single-aisle jets, favored by low-cost carriers, will account for about 70 percent of the 36,770 planes that Chicago-based Boeing estimates will be sold by all companies through 2033, according to its annual market outlook released Thursday.