Updated

Machinists at Boeing Co. (search) approved a new labor contract on Thursday, ending a four-week strike that shut down the company's commercial airplane assembly plants.

About 80 percent of those voting accepted the three-year pact, said Mark Blondin, president of Machinists District Lodge 751 (search). Approval cleared the way for workers to return to their jobs as early as Thursday night.

"You stood up and said no to corporate greed," Dick Schneider, the Machinists' aerospace coordinator, told a cheering crowd of several dozen union members. "We hope this is a wake-up call to corporate America!"

A simple majority was needed to accept the offer. Union leaders had recommended that membership vote for the deal, saying it addressed key issues — pensions and health care benefits.

The average Machinist represented by the contract is 49 years old and makes about $59,000 a year.

The strike by about 18,400 Machinists began Sept. 2.

Under the new contract, workers will see no changes to current health care premiums. Pension payouts will increase by nearly 17 percent, to $70 per month for every year worked.

Instead of any general wage increase, the revised offer gives Machinists in the Seattle area, Gresham, Ore. and Wichita, Kan., cash payouts of about $11,000 over the three years. Boeing dropped a plan to offer incentive payments based on whether the company meets or exceeds financial targets.

"To me, this is a win," said Kent Sprague, 51, a Boeing machine repairman who voted for the contract. "I'm a little disappointed that Boeing didn't offer this initially."

The Chicago-based company said the total cost of the new offer was similar to the proposal rejected by Machinists at the start of the strike.

"We're very pleased with today's contract ratification by our machinists and look forward to their return to work," Alan Mulally (search), president and CEO of Boeing Commercial Airplanes, said in a statement. "Our focus now shifts to ensuring a smooth restart of our production system and a return to a steady flow of airplane deliveries to our customers.

"Boeing Commercial Airplanes is healthy and competitive," Mulally added. "We have tremendous momentum in the market and a very bright future."

While workers can resume their jobs immediately, they won't be required to return to work until Oct. 12.

Union spokeswoman Connie Kelliher said some workers have taken temporary jobs and will need time to finish them.

Boeing Chief Financial Officer James Bell said earlier that more than two dozen airplanes wouldn't be delivered in September because of the strike.

Still, analysts expect the company to be able to make up for any lost airplane production relatively quickly.

Analysts hadn't expected the strike to immediately push customers to dump Boeing in favor of rival Airbus SAS (search). But many said it was still important for Boeing to get workers back on the job quickly. Boeing saw a sharp downturn in commercial airplane business following the 2001 terrorist attacks and was forced to lay of thousands of employees, but business has improved in recent months.