Boeing Co. has won a contract valued at $4 billion for fighter jet fleet upgrades for the Saudi Arabian Air Force, the Pentagon said on Friday.

The procurement order covers conversion of 68 F-15s to Saudi Air Force specifications, and four base stand-up kits.

The Pentagon said the work, expected to be completed by December 31, 2019, would be done at Robins Air Force Base in Georgia.

(Reporting By Ros Krasny)