COLUMBUS, Ohio — The military is ordering more lightweight armor developed in Ohio that the armor protects troops in Humvees from automatic weapons fire and grenades without slowing the vehicles.

Unarmored Humvees have become targets in the war in Iraq. The vehicle was designed to carry troops and supplies, not be part of the fighting. Special-operations forces were looking for lighter armor that doesn’t affect their speed or make Humvees too heavy to transport on planes.

Some Humvees are being equipped with up to 3,000 pounds of armor, which slows them down. The new armor offers less protection, but weighs 750 pounds.

The military has tested 75 of the armor kits in the Middle East and has ordered 400 more from Columbus-based Battelle, the world’s largest independent, nonprofit research institute.

Battelle introduced the armor kits last week at the Naval Institute’s ninth annual Warfare Exposition and Symposium in Virginia Beach, Va.

“The bad guys come up with newer tactics, and we come up with newer techniques,” said Skip Dirren, who heads Battelle’s Navy marketing operations.

With no time to invent armor, Battelle went to the marketplace and found that an armor made of polyethylene and titanium survived testing at its laboratory.

The armor is 15 times stronger than steel, according to John Bockbrader, project manager. His team of engineers adapted the armor to fit Humvee parts oftervulnerable, including doors, seats, wheel wells and the underbody.

The armor will not stop blasts from homemade bombs and rocket grenades that Iraqi insurgents have repeatedly used.

But the lighter armor will help, said 1st Lt. Tim Casteel, who returned to Ohio Sept. 3 from a 15-month tour in Iraq.

During Casteel’s last three months in Iraq, his Middletown-based unit, the 324th Military Police Company, escorted truck convoys, he said.

His group rode in Humvees loaded with so much ceramic armor that the cargo trucks they escorted could accelerate faster in an attack, he said.

“When you’re attacked, you have to have the ability to hit the gas pedal and go and not be stuck at 45 to 50 mph,” Casteel said.

The government has paid Battelle $25 million to work on the armor during the past three years. Battelle is selling it to the Defense Department for $90,000 to $120,000 per kit.

Traditionally, 90 percent of Battelle’s business is contract work for the federal government.