Wichita ? Technical and professional workers at Boeing Co.’s Wichita plant soundly rejected the company’s latest contract offer Monday, heeding the advice of their beleaguered union.

The Society of Professional Engineering Employees in Aerospace had recommended workers turn down the proposal so contract negotiations could resume.

Their membership did just that by a 74 percent majority. The vote was 904-319 to reject the contract, the union said. The mail-in ballots were counted Monday.

Union officials said they were pleased with the results, which would strengthen their position when they return to the bargaining table in about two weeks.

Boeing spokesman Fred Solis said the company stood behind its offer.

“It is our final offer — at least that is what I am told,” Solis said. “If the union wants to be back to the negotiation table, we will accept their invitation and listen to what they have to say,” Solis said.

The union’s recommendation came after a contentious decertification vote last month that narrowly left union representation in place.

In an unprecedented move, the union also sent out 1,500 “advisory ballots” to nonmembers who are represented by the union to get a sense about their thoughts on the contracts. The advisory ballots, which did not count toward a decision, showed 68 percent of nonunion workers also would have rejected the contract if they could have officially voted.

“We never did that before,” said Bob Brewer, Midwest director of the union. “We just came off the decertification vote; we had a lot of people feel they weren’t included.”

Brewer said the company and the union would return to the bargaining table in a couple weeks.

About 3,450 union workers at the Wichita facility have been working under an extension since a three-year contract expired Feb. 19.

The contract offer included wage increases of 3.5 percent in the first year and 3 percent in each of the next two years. Employees would pay significant increases in two of three available worker health plans. Under the traditional plan, for example, family coverage would have gone up from $30 a month to $156 per month. The contract offer also did not include an employee incentive plan Boeing offers to nonrepresented workers.

“If you look at this contract, versus what everybody else got, it looks like we were singled out. … Everything about this contract is not where it should have been,” Brewer said.

Boeing said the offer was based on the state of the industry and market conditions locally.

“Our focus continues to be on balancing the needs of employees with the company’s ability to compete,” Solis said.