Boeing is close to striking a deal with the Chinese government to open a 737 jet completion and delivery centre in China, The Seattle Times reported.
According to a person familiar with the details, an announcement could be made during president Xi Jinping's visit to Seattle on 23 September.
Leaks of the news caught elected officials, unions and industry leaders in Washington state by surprise.
Reuters reported that the governor's office, labour leaders and industry associations claimed to be unaware of the developments.
Final assembly of the 737 airframes would continue in Renton, which employed around 12,000 people, about half of those production workers.
However, jets destined for Chinese carriers - between a quarter and a third of all 737s built, would fly empty to a new Chinese facility for installation of interiors, exterior painting, customer flight tests and delivery, a person familiar with the plan said.
A deal of the type would create Boeing's most significant overseas commercial-aircraft venture, which would grant it new leverage in the world's biggest aviation market.
Though Boeing had long had an extensive global supply chain, this would be the first time its jets would be finished and delivered outside the US.
According to the person familiar with the plan, details such as which Chinese company Boeing would partner, where the facility would be set up and when it would open were still under discussion.