Boeing made a decision on Monday that the company had long resisted: to temporarily stop producing its most popular passenger jet, the 737 Max, which has been grounded for nine months in the wake of two crashes that killed 346 people.

The impact of that decision is stretching far beyond Boeing’s headquarters in Chicago and its giant production facility in Renton, Wash., rippling through the worldwide aerospace supply chain from California to Kansas, Britain to France. For Boeing’s vast network of suppliers, the announcement made real what they had dreaded — a suspension of unknown length that could force some of them to scale back production and even lay off workers.

“The uncertainty around the airplane is a challenging thing at the moment,” said Phil Anderson, who runs a small aerospace supplier that has facilities in Wichita, Kan., and depends on the Max for 50 percent of its annual revenue. “All the options are on the table.”

Boeing purchases the parts that go into the Max from 600 companies, including major corporations like General Electric, which supplies engines for the airplanes, and lesser-known manufacturers that specialize in components like lighting systems and seats.