Boeing Co. said Monday it is suspending production of its best-selling 737 Max jetliner in January, its biggest assembly-line halt in more than 20 years, as the consequences of two fatal crashes of the now-grounded aircraft look set to drag into 2020.

Boeing, which builds the 737 south of Seattle, said it would not lay off any of the roughly 12,000 employees there during the production freeze, though the move could have repercussions across its global supply chain and the U.S. economy.

The decision, made at a two-day board meeting, came after the Federal Aviation Administration refused to approve the jet's return to service before 2020 and delivered what was seen as a public rebuff to Boeing's hopes of moving faster.