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,

The latest round of talks between Boeing and machinists, mediated by federal officials, broke off without progress, according to the union.