Oshkosh Truck Corp. today reported that third quarter net income increased 57.4% to $21.6 million on sales of $489.5 million. Sales increased 20.6% in the third quarter. Operating income increased 39.5% to $38.4 million. The company's third quarter performance included a $4.5 million increase in operating income to record a cumulative adjustment to margins recognized on its multi-year Medium Tactical Vehicle Replacement (MTVR) vehicle production contract. This increase was a result of events in the third quarter, including the completion of a retrofit program to bring low-rate production vehicles to final configuration, sustained positive cost performance and negotiation of a modification to the MTVR contract it has with the U.S. government to include "dump and wrecker body" variants. "A contract modification to the MTVR contract during the quarter to include dump truck and wrecker models should assure the production of more than the base quantity volumes under the contract, assuming the government approves funding of the wrecker models," president & CEO Robert G. Bohn said.