OSHKOSH, WI (WTAQ) - Shares of Oshkosh Corporation jumped nearly 19 % Friday after the Wisconsin company revised its fiscal 2013 earnings outlook upward.

The maker of trucks and life equipment reported a strong first quarter profit led by sales in the construction field.

Oshkosh reported a profit of $46.5 million for the quarter ending December 31st.

Total sales were down a little over 6% due to a decline in its military business.

Though first-quarter sales in Oshkosh’s military business was off significantly, operating profit margins were much higher than expected