FILE PHOTO - A view of the main entry way at the Oshkosh plant in Wisconsin October 12, 2011. REUTERS/Darren Hauck

WASHINGTON (Reuters) - Oshkosh Corp OSK.N has been awarded a $1.7 billion modification to a U.S. defense contract to exercise options for 6,107 vehicles and 22,166 kits, the Pentagon said on Tuesday.