Boeing is shaking up its shrinking defense division, putting some executives into new roles and reducing the number of managers.

It’s also disbanding its Missiles and Unmanned Airborne Systems division, spreading its work out among other Boeing units.

Boeing makes military helicopters and planes, in addition to commercial jets used by airlines. The commercial airplane business has been expanding. But the defense business is suffering because of tight government spending in the U.S. and other countries.

The company has about 500 suppliers in Ohio and spends $4.8 billion annually in the state, according to Boeing officials.

Boeing is reducing the number of defense executives by 30 percent from 2010 levels. Spokesman Todd Blecher said much of that has already happened, and the last 10 percent of the cuts will come by the end of the year.

Boeing reassigned several defense executives on Wednesday as part of the restructuring.

The job cuts weren’t expected to have an immediate impact on workers in Dayton or Ohio, Blecher said.

The aerospace giant employs about 600 workers in the state, he said. Employment figures for Dayton weren’t immediately released, but a small company field office works with Wright-Patterson, he said in an email.

The Boeing Guidance Repair Center in Heath is a key worksite center in Ohio, while company employees work with NASA at the Glenn Research Center in Cleveland on the next generation Space Launch System.

The Air Force Life Cycle Management Center, headquartered at Wright-Patterson, has a $4.9 billion contract with Boeing to assemble the first 18 KC-46 aerial tankers by 2017, according to base spokesman Daryl Mayer.

“It’s safe to say we do quite a bit of business with them,” Mayer said.

The Air Force expects to buy 179 refueling tankers, the service’s number one acquisition priority, he said. The jet would replace aging, 1950s-era KC-135 Stratotankers.

The shake-up includes disbanding the Missiles and Unmanned Airborne Systems division as of Jan. 1. That unit makes things like cruise missiles and drones that have been in high demand but which are not needed as much as the wars in Iraq and Afghanistan have wound down.

Barrie Barber contributed to this story.