Wichita ? Technical workers at The Boeing Co.’s Integrated Defense Systems plant in Wichita voted Tuesday to decertify their union, immediately ending representation for about 900 employees.

Petitioners seeking to get rid of representation by The Society of Professional Engineering Employees in Aerospace won the election 408-353, the union said.

An engineering unit representing 700 at Boeing’s IDS plant here was not included in the vote and remains under SPEEA representation.

Organizers of the effort to get rid of the union contended nonrepresented workers pay less for benefits and get incentive benefits not paid to unionized workers.

One of the major issues that led to the decertification vote has been the employee incentive plan, which excludes the unionized employees at the plant.