Boeing Co. said it would suspend production of its 737 MAX jetliner, in an escalation of the crisis facing the giant plane maker that will ripple through the global aerospace industry.

The company said Monday that it plans to halt production in January, having assembled around 40 planes a month at its plant near Seattle since the MAX was grounded globally in March following two fatal crashes of the aircraft within five months. The two accidents in Indonesia and Ethiopia claimed a combined 346 lives.

Chicago-based Boeing plays a big role in the U.S. economy: It is the largest U.S. manufacturing exporter and one of the nation’s top private employers. And the MAX is its best-selling plane.

The plane maker employs around 12,000 workers at its 737 assembly plant in Renton, Wash. Production of the 737 MAX also supports thousands of jobs across a network of over 600 suppliers and hundreds of other smaller firms in the global MAX supply chain.

Boeing said that it planned to reassign its workers and didn’t expect furloughs or layoffs. The company didn’t share details on the expected duration of a production shutdown that will impact suppliers around the world.