A Boeing 737 aircraft is seen during the manufacturing process at Boeing's 737 airplane factory in Renton, Washington, May 19, 2015. A couple of shareholder resolutions are seeking the split of Boeing’s CEO and chairman positions in the aftermath of the 737 Max crisis. Saul Loeb/AFP/Getty Images

Boeing Co.’s engineers’ union formally approved a six-year labor contract Wednesday, avoiding a recap of a bitter and contentious months-long negotiation process over the last contract in 2012. More than 70 percent of engineers and technical workers from the Society of Professional Engineering Employees in Aerospace (SPEEA) approved the contract, the union said in a statement Thursday.

The agreement, which is set to come in force after the current one expires in October, included a 5 percent annual compensation boost over five years , along with improved vacation time and provisions for new layoff benefits for employees.

The company also promised to pay its engineers at least 15 percent more than their peers at non-Boeing companies make — and to pay its technical workers a 22 percent premium to the market. While the majority of the 20,100 workers are at Boeing facilities in the Puget Sound region, the contracts also cover workers in Oregon, Utah, California and Florida.

However, the aviation giant phased out its traditional pension plans in Wednesday’s contract. While employees hired with pension benefits will be allowed to keep what they've earned, going forward, Boeing will phase out defined benefit pensions and switch all SPEEA workers into "enhanced" 401(k) plans.

The agreements "grew from a strong desire on both sides to find common ground and negotiate contracts that work for SPEEA members and Boeing," said Ryan Rule, president of the union. "It was a unique opportunity that allowed these early contract talks," he added. "We're glad it worked."

Boeing and SPEEA announced that they had reached a tentative agreement earlier in January, reportedly following months of secret negotiations. Boeing thanked its employees Thursday and said in a statement, "This agreement helps position us for continued success in a highly competitive landscape."

On Wednesday, Boeing’s CEO Dennis Muilenburg reportedly reaffirmed the company’s outlook for strong growth over the next five years at an investor conference, dismissing notions that the aviation industry was close to a downturn.