Boeing also confirmed mediation would continue on Tuesday. The union is seeking a 40% pay rise over four years and the restoration of a defined-benefit pension that was taken away in the contract a decade ago.

Boeing delivered 33 new aircraft to customers in September in spite of a labor strike of Seattle-area workers that has shuttered two major assembly plants, the company said Tuesday. Boeing also delivered four 787 Dreamliner planes,

Boeing delivered fewer airplanes in September compared with recent months and past years, as it felt the first effects of the ongoing Machinists strike.