Boeing Co has made an early deal with its biggest union for a new four-year contract, which if ratified would mean the end of the planemaker's dispute with the National Labor Relations Board and ensure the new 737 MAX single-aisle plane would be built in Washington state.

The agreement, coming nine months before the expiration of the current contract, would give Boeing some comfort that strikes will not disrupt its operations as it ramps up production of many of its models, and it would give the union the local jobs for which it has campaigned.

The 28,000 members of the International Association of Machinists & Aerospace Workers will vote on the contract deal next week, the union said on Wednesday.

If ratified, the union said it would drop its grievances against the company over its establishment of a new 787 production site in South Carolina, which is the subject of a dispute between Boeing and the NLRB.

Boeing's shares rose 4.4 percent in a generally higher market.

(Reporting by Bill Rigby, editing by Gerald E. McCormick)