Contracts are part of a planned overhaul of the US nuclear arsenal.
Announcement signals that revenue growth challenges will continue.
Competing for deal against three other international partnerships.
The highly-classified $55 billion project will replace aging bombers with an information-age aircraft that could fly without a pilot aboard.
Report says operations and fighting software face 13-month delay.
Aerospace giant will close California assembly plant.
Aerospace manufacturer will provide landing gear and overhaul services to US Air Force aircraft over four years.