(Reuters) -Striking workers at Boeing Defense's St. Louis-area facilities voted to approve the company's latest contract offer on Thursday, union officials said, ending a 101-day strike that has hampered production of fighter jets and other programs.

The roughly 3,200 members of the International Association of Machinists and Aerospace Workers (IAM) District 837 will start returning to work as early as Sunday.

"IAM District 837 members stood strong and united for over three months," union leaders said in a statement. "We're proud of what our members have fought for together and are ready to get back to building the world's most advanced military aircraft."

Details on the union vote were not yet available.

"We're pleased with the results and look forward to bringing our full team back together on Nov. 17 to support our customers," a Boeing ( BA ) spokesperson said in an email.

The workers assemble Boeing's ( BA ) F-15 and F/A-18 fighter jets, the T-7 trainer aircraft, munitions and wing sections for the 777X commercial jet. The strike, which began on August 4, has disrupted F-15 deliveries to the U.S. Air Force and slowed production across several key programs.

District 837 members had pushed Boeing ( BA ) for a higher ratification bonus and improved retirement plan contributions - closer to terms in Boeing's ( BA ) deal reached last year with Seattle-area IAM members after a 53-day strike.

Boeing ( BA ), however, throughout the strike, refused to increase the value of its offer, which includes a 24% general wage increase over five years. 

On Monday, Boeing ( BA ) unilaterally revised its offer, reducing the overall bonus. It increased the upfront cash incentive to $6,000, up from $3,000 in the previous proposal, but cut another $4,000 in bonuses that would have been paid later during the contract's term. The rest of the offer remained largely unchanged from earlier versions that had been rejected by union members.

UNION MEMBER SAYS MANY 'FATIGUED' BY THE STRIKE'

The company simply outlasted its wage-earners, District 837 member Brandon Thiel told Reuters. "They're basically bullying us with the fact that they have more disposable income than most of us do."

He said he voted to reject the offer. 

Many fellow IAM members were "fatigued" by the strike and worried about the upcoming holidays, he said. "Nobody wants to give their kids a crappy holiday."

Speaking publicly in July, Boeing ( BA ) CEO Kelly Ortberg dismissed any concern about the strike impacting the company. 

"I wouldn't worry too much about the implications of the strike. We'll manage our way through that," he said.

Workers at the facilities went on strike in August after rejecting a second offer from the company. 

Boeing ( BA ) was criticized by both Republican and Democratic lawmakers in Congress, who urged the company to negotiate with the union. 

The IAM had filed an unfair labor practice charge with the National Labor Relations Board in October, accusing the planemaker of negotiating in bad faith.