(Reuters) – Boeing Co’s largest supplier Spirit AeroSystems Holdings Inc reported strong first-quarter results on Wednesday, while following the planemaker in suspending its full-year outlook in the face of the global grounding of 737 MAX jets.

The crisis with Boeing’s most popular aircraft has thrown into doubt orders for a raft of parts makers who have been investing heavily to meet record-breaking demand from the world’s biggest planemaker over the past two years.

Spirit, which makes fuselage, structural engine components and wing parts for the MAX, did a deal with Boeing last month to stick to its current parts delivery schedules for now, and its profits in the first quarter were up 30 percent, according to Wednesday’s quarterly results.

Boeing however has announced cutbacks in