China on Monday ordered domestic airlines to suspend commercial operation of the Boeing 737 MAX 8, citing the Ethiopian Airlines crash and another deadly accident of that same model in Indonesia. Image Credit: AFP

Shares in Boeing Co’s biggest European suppliers, Senior Plc and Safran, fell sharply on Tuesday after the U.S. planemaker said it would suspend production of its best-selling 737 MAX jetliner in January, deepening its crisis.

Boeing said on Monday it would temporarily stop producing the jets in January, its biggest assembly-line halt in more than 20 years, as fallout from two fatal crashes of the now-grounded aircraft drags into 2020.

At 0844 GMT, Safran shares in Paris were down 3.6% at their lowest since early September.

With General Electric, the French company produces engines for the 737 MAX and unlike most suppliers is paid mostly once the airplanes are delivered to the airline buyer.

Shares in Senior, which makes parts including airframes and engine build-up tubes for the jets, were down 7.4% at the bottom of London’s FTSE 250 index. Its aerospace unit counts Boeing as its biggest customer.

“This is clearly not a helpful development for Senior, and although the group has reduced its exposure to the platform in the last few months and this is a temporary pause, the 737MAX remains an important platform,” said Jefferies analyst Andy Douglas.

Airbus shares were up 1.6% in early trading.

Other smaller suppliers were also lower. Melrose Industries , whose GKN business has a contract to supply windows for the passenger cabin of the 737 MAX until the end of 2025, also fell more than 1%.

Shares in Spirit AeroSystems Holdings Inc, Boeing’s top supplier, fell 1.6% in the United States on Monday.