SEATTLE — Despite warnings that production of Boeing’s next generation 777 plane could go to another state, machinists in the Northwest voted to reject a contract proposal late on Wednesday that would have exchanged concessions for decades of secure jobs.


In response, the Boeing Co. said it would begin a bid process to find a home for its 777X production line.


Members of The International Association of Machinists District 751 rejected the proposal with 67 percent of the votes. Union members who called for a no vote did so in protest of Boeing’s push to end a traditional pension plan and increase their health care costs. Workers would have received a $10,000 signing bonus if they approved the deal.


“We preserved something sacred by rejecting the Boeing proposal. We’ve held on to our pensions and that’s big. At a time when financial planners are talking about a ‘retirement crisis’ in America, we have preserved a tool that will help our members retire with more comfort and dignity,” said Tom Wroblewski, District 751 president in a statement.


Boeing had proposed the eight-year contract extension, saying it needs the deal to assemble the new 777X in Washington state. With the threat of those jobs going to another state, lawmakers rushed to approve $8.7 billion in tax breaks last week.


“...Without the terms of this contract extension, we’re left with no choice but to open the process competitively and pursue all options for the 777X,” Boeing said in a statement.


In a late night press conference, Gov. Jay Inslee said Washington state could have won the production of the plane without competition. The proposal’s rejection means that Boeing will look at states, such as Texas, that have Right-To-Work laws, which halt unions.