Boeing shares fell as much as 6% on Wednesday.
CEO Kelly Ortberg announced that stabilizing 737 MAX production is taking longer than anticipated. The company is currently working to steady output at 47 jets per month.
Constraints at the wing production facility caused the delay. Ortberg noted the broader supply chain remains in good shape to support future rate increases.
Boeing plans to increase monthly production to 52 jets once the current rate stabilizes. Certification for the 737-10 variant is expected very soon.