Boeing is planning to suspend production of its beleaguered 737 Max planes next month, the company said Monday, December 16, a drastic step after the Federal Aviation Administration said its review of the planes would continue into next year, CNBC reports.

Boeing’s decision, made after months of a cash-draining global grounding of its best-selling aircraft, worsens one of the most severe crises in the history of the century-old manufacturer.

The measure is set to ripple through the aerospace giant’s supply chain and broader economy. It also presents further problems for airlines, which have lost hundreds of millions of dollars and canceled thousands of flights without the fuel-efficient planes in their fleets.

Boeing said it does not plan to lay off or furlough workers at the Renton, Washington, factory where the 737 Max is produced during the production pause. Some of the 12,000 workers there will be temporarily reassigned.

Boeing last week acknowledged that regulators’ review of the planes — grounded since March after two crashes killed 346 people — would last until the following year, longer than the end-of-year approval the Chicago-based manufacturer was targeting.

Just how long Boeing will keep its 737 Max production line halted was not immediately clear, because it will depend on when regulators clear the plane to fly again. U.S. airlines have taken the planes out of their schedules until at least March. American last week said it doesn’t expect to fly the planes before April.