Boeing is furloughing tens of thousands of white-collar employees in an effort to cut costs and avoid a credit-rating cut in the midst of a strike by its largest union.The jet maker will furlough affected employees for one week out of every four weeks for the duration of the walkout,

The strike at Boeing by 33,000 members of the International Association of Machinists union, which reaches its seventh day today, has already cost the company and workers $572 million, according to an estimate from Anderson Economic Group.

Boeing’s CEO says the company will begin furloughing a large number of employees to save cash during a strike by union machinists.

Boeing operates its defense business, which is in a separate unit from the company’s commercial plane segment, in the St. Louis area. There are about 15,000 Boeing workers here.

Affected employees will take one week of furlough every four weeks on a rolling basis as long as the strike lasts.

Boeing is temporarily furloughing executives and other nonunion workers to save cash during the strike by 33,000 members of the International Association of Machinists, CEO Kelly Ortberg told employees in an email Wednesday.

Boeing may prevent its debt being downgraded to junk by issuing more stock, which would deal another blow to current shareholders.

Nonunion employees will experience one-week furloughs every four weeks as the troubled planemaker struggles to conserve cash.

About 33,000 Boeing factory workers represented by Districts 751 and W24 of the International Association of Machinists and Aerospace Workers union (IAM) announced on September 12 its members had voted 94.6% to reject a contract offer from the company and 96% for a strike.

Selected employees will take one week of furlough every four weeks on a rolling basis, Kelly Ortberg, the CEO of Boeing, wrote in an email.