EVERETT — The Boeing Co. resumed negotiations with its engineers union in hopes of avoiding a second strike Monday as its Machinists returned to work after nearly two months on strike.

Leaders for Boeing and the Society of Professional Engineering Employees in Aerospace discussed workers’ wages for a new contract Monday after recessing for the weekend. The union’s contract expires Dec. 1.

“Every SPEEA-represented employee should receive a market leading salary,” said Ray Goforth, SPEEA’s executive director.

Serious contract talks between SPEEA and Boeing were delayed slightly last week to give the company time to reach a tentative deal with its Machinists union. Boeing’s 27,000 Machinists began reporting back to work late Sunday and on Monday after 57 days on strike. The strike cost Boeing an estimated $100 million daily in deferred income. The Machinists ratified the contract Saturday with 74 percent of members who voted approving the four-year deal.

“While the strike has been difficult for everyone, our challenge now is to restart our production and regain our momentum,” said Scott Carson, Boeing’s president of commercial airplanes, in a message Saturday.

Analyst Scott Hamilton estimated Monday that the strike delayed the delivery of approximately 80 Boeing aircraft. The jet maker had handed over 36 jets to customers in both August and July. But the Sept. 6 walkout slowed deliveries in September to 12. Boeing executives last month noted that there would be a ramp-up period for production. Machinists have until Monday to report back to work.

Company officials haven’t yet disclosed the impact of the strike on Boeing’s new 787 Dreamliner jet, which already was 15 months behind schedule when the strike began. The aerospace company would stack up even further delays on its 787 if its engineering and technical workers strike. SPEEA negotiators have expressed frustration over similar issues as the Machinists.

SPEEA’s Goforth noted his take on the Machinists’ strike in a brief text message sent to members Sunday.

“After 57 days, 26 percent of IAM members vote to continue strike,” Goforth wrote. “Boeing’s return on investment by provoking strike? Years of morale problems.”

Boeing has moved to relieve any resentment SPEEA members harbor over the company’s use of outsourcing. Boeing allowed suppliers to design sections of the 787 that traditionally had been done in house.

But Mike Denton, Boeing’s vice president of engineering, said recently that the company likely will do things differently on its next new airplane. Boeing already had to pull design work back from 787 partners both for the 787-8 and the 787-9 models.

“We really think we need to own some part of major production,” Denton said.

Boeing plans to present its final offer to the union by mid-November. SPEEA represents about 20,500 engineers and technical workers.

Boeing shares closed at $52.85 Monday, up 40 cents for the day. Negotiations between Boeing and SPEEA continue today.

The Associated Press contributed to this story.

Reporter Michelle Dunlop: 425-339-3454 or mdunlop@heraldnet.com.