Spirit's total deliveries of shipsets, or complete sets of parts, fell 48.9% to 231 units in the fourth quarter. Boeing 737 MAX deliveries fell to 19 shipsets from 153 a year ago.
European planemaker Airbus last week forecast flat deliveries in 2021 as it braces for more coronavirus-induced uncertainty in the wake of an annual loss. Boeing has yet to set out detailed targets.
Spirit posted a loss of $295.9 million, or $2.85 per share, in the quarter ended Dec. 31, compared with a profit of $67.7 million, or 65 cents per share, a year earlier.