Wichita ? The union of technical and professional workers at Boeing Co.’s Wichita plant overwhelmingly rejected the latest contract offer from the company on Friday, and by an even larger margin authorized a strike.

The vote gives the Society of Professional Engineering Employees in Aerospace leverage in upcoming contract talks, slated to begin the week of June 7, said Bob Brewer, the union’s Midwest director. He added that the vote to authorize a strike does not mean one is imminent.

“A strike is in nobody’s best interest,” Brewer said. “If it comes to that, the negotiating team could call a strike. The bottom line is, we’re real disappointed and disheartened Boeing has put all of us in this position.”

More than 70 percent of union members voted against the contract. The vote was 867-365 to reject the contract, SPEEA said. But nearly 75 percent voted to authorize a strike. That vote was 920-309.

In March, heeding the advice of their beleaguered union, Boeing’s technical and professional workers rejected a contract offer by a 3-to-1 margin. Union officials said the new contract proposal offered the same wage increases.

Boeing spokesman Fred Solis said the company was disappointed with the vote on a contract Boeing believes is “equitable, competitive and market-leading.”

“We think it’s a good offer, a fair offer,” Solis said. “I understand that they are interested in going back to the table, and we’ll certainly make ourselves available for that.”

He said Boeing has contingency plans in case of a strike, but the company hopes the negotiations don’t come to that.

The three-year contract covers 3,400 workers at the company’s Wichita plant. It offered workers a 3.5 percent salary increase in the first year, followed by 3 percent annual increases in subsequent years.

Premiums for traditional health care plans would have increased 15 percent in the first year and 18 percent in subsequent years. The company would still offer a no-contribution plan, which provides the same benefits as the other company plans through a network of health care providers.

Brewer said the biggest differences between the company and union in contract talks are philosophical.

“Boeing has said, ‘Hey, instead of partnership, we’re going into power-based negotiations,”‘ Brewer said. “We’re saying, ‘OK, we can do that.’ To what extent everybody really means that remains to be seen.”