The changes, which had been anticipated by analysts, reflected continued strong demand for Boeing's single-aisle 737, and slower orders for the twin-aisle 777.

They also came amid concerns that demand for new aircraft is slowing as the global economy cools and sharply lower oil prices make older, gas-guzzling planes more economical to fly.

Boeing Chief Executive Officer Dennis Muilenburg countered the concerns on a conference call on Wednesday after Boeing posted disappointing earnings that sent its stock down as much as 10 percent.

"Based on discussions with our customers, lower oil prices have not substantially changed their views on future fleet planning or their commitment to existing delivery schedules," he said.

Muilenburg said Boeing expects a 2016 book-to-bill ratio of "approximately 1," in line with 2015, meaning new orders will roughly match deliveries.

Boeing shares were down 6.8 percent to $119.36 after falling as low as $115.02.

(Reporting by Alwyn Scott in Seattle; Editing by Jeffrey Benkoe)

By Alwyn Scott