SEATTLE — Federal labor law regulators have reportedly dismissed charges filed by members of the Machinists union against Boeing alleging the company used illegally pressured them to approve a new contract in January, reports Reuters.

Workers filing the complaints said that the aerospace giant had engaged in unlawful bargaining by telling workers that if they didn’t approve the concession-laden contract, the company would not put the assembly line for its new 777X jetliner in Washington.

About 20 complaints were filed with the U.S. National Labor Relations Board’s Region 19 office, which is based in Seattle.

The NLRB dismissed the charges last week after finding “insufficient” evidence of any illegal threats by Boeing, an NLRB official told Reuters.

Federal regulators had already dismissed more than 30 charges filed by local Machinists against the headquarters of the International Association of Machinists and Aerospace Workers (IAM), alleging that it had overstepped its authority in forcing a contract vote against the objections of local union leaders.

The contract required workers to give up too many benefits that had been hard won during previous negotiations with Boeing, local union leaders said at the time.

Opponents of the contract said that Boeing had to put 777X production in metro Puget Sound, so union members should vote no on the offer and renegotiate from a position of strength.

The union’s top leaders had a much more pessimistic view from its headquarters in Upper Marlboro, Maryland. Worried that Boeing would set up 777X production in a non-union state, the International — as the IAM’s leadership is called — forced a vote in January.

Workers narrowly approved the contract on Jan. 3, and Boeing announced in February that the 777X will be assembled in Everett.

Dan Catchpole: 425-339-3454; dcatchpole@heraldnet.com; Twitter: @dcatchpole.