The company says the layoffs are necessary because of an anticipated slowdown in spending by the defense department.
Of the 23,000 aerospace workers, 18,000 are based in Southern California.
The company says employees have until Sept. 15 to volunteer for layoffs that will be based on seniority and include a lump-sum payment and extended medical insurance benefits. Involuntary layoffs will follow if needed.
The company says it has about 450 job openings in the aerospace division, but they are mostly contract-funded jobs.
The news of the cutbacks comes the same week that Northrop Grumman moved its corporate headquarters from Century City to Falls Church, Virginia.
The Associated Press contributed to this report.
