But results of the evaluations haven't been released and manufacturers are still waiting for the program office to issue a request for proposals — initially expected this month — to begin the next round of competition.

Defense contracting giant Lockheed Martin Corp., truck-maker Oshkosh Corp. and Humvee-maker AM General LLC each delivered 22 JLTV prototypes to the Army for testing under engineering and manufacturing development contracts signed in 2012. Now, the companies are competing against each other to build 17,000 of the vehicles under a much bigger low-rate initial production contract.

"Our JLTV solution draws upon real-world experience gained from supporting the ground operations that our soldiers and Marines perform every day," Oshkosh Defense President John Urias said in a release announcing the end of limited-user testing, or LUT. The firm has built the Army fleets of medium– and heavy-duty and blast-resistant trucks.

Jeff Adams, a spokesman for AM General, said the company has completed every milestone throughout the EMD phase, including LUT. "We are very pleased with the BRV-O's performance and its demonstrated ability to fill the Capability Gap in Light Tactical Vehicles and look forward to the program down-select decision expected sometime in mid-2015," he said in an e-mail.