The International Association of Machinists has ordered the local representing Boeing employees in Seattle to hold another contract vote.
An IAM official said the vote on Boeing's latest offer is scheduled Jan. 3, the Seattle Times reported.
District 751 in the Seattle area posted a message on its website Saturday urging members to reject the contract.
"Because of the massive take-aways, the Union is adamantly recommending members reject this offer," local officials said.
District 751 members rejected a previous contract offer Nov. 13. Boeing then announced it was considering manufacturing its 777X plane elsewhere.