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,

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.