U.S. eyes deal with S.Korea on F-16 upgrades by year-end -sources

WASHINGTON, Sept 5(Reuters) - The U.S. government hopes to hammer out an agreement with South Korea by the end of the year for the U.S. unit of Britain's BAE Systems Plc to carry out $1 billion-plus of upgrades to more than 130 F-16 fighter jets, sources familiar with the discussions said this week.