Boeing's Integrated Defense Systems in Wichita is taking longer than first planned to reduce employment by 800 jobs.
A year ago, Boeing Wichita officials said the company would cut 800 jobs by mid-2009 as work on some existing programs wound down.
But by the end of 2009, Boeing Wichita will have cut 500 of the 800 positions.
The company issued 60-day layoff notices to 77 employees on Friday.
The remaining 300 or so layoffs will take place by mid-2010, when work on refueling tankers for Japan and Italy winds down, said Boeing Wichita spokesman Jarrod Bartlett.
"Unfortunately, we haven't been able to mitigate (the layoffs) altogether," Bartlett said.
The number may fluctuate some, he said. But "that's the number that we're sticking with."
Boeing is modifying 767 aircraft into tankers for Italy and Japan.
So far, Boeing has delivered three tankers to Japan and has one more to deliver. Four tankers are to go to Italy. Boeing Wichita is performing modification work on the tankers.