The National Labor Relations Board announced Friday its approval of the withdrawal of a charge by the machinists union against the Boeing Co.

The International Association of Machinists and Aerospace Workers, representing about 31,000 Boeing workers in Washington state,  earlier had accused the multinational aerospace and defense corporation of defying federal labor law and illegally retaliating in response to the union's previous strikes by constructing a nonunion plant in South Carolina instead of Washington .

The union asked the NLRB to terminate the case and remove all charges following its signing of a collective-bargaining agreement with the company.

As per the deal, the union agreed to withdraw all charges in return for Boeing's choosing to build a new version of its 737 airplane in Washington. It is a four-year contract extension that was signed last week.

The union asked to withdraw the charge following the ratification of a four-year collective-bargaining agreement between its members and Boeing earlier this week. Based on that request, the administrative law judge presiding over the case dismissed the complaint and remanded the case to our regional office in Seattle for further processing, Lafe Solomon, the NLRB acting general counsel, said in a statement.

Solomon mentioned that this is the outcome the NLRB always preferred and noted that around 90 percent of the board's meritorious cases are resolved as a result of agreements between the parties or settlements with the agency before the conclusion of litigation.