Six civilian employees and a subcontractor at Kelly Air Force Base were arrested in a sting operation and charged with stealing more than $50,000 in government equipment, from jet engine parts to telephones, investigators said.

Authorities said the property was sold at only 5 percent of its value to federal undercover agents posing as subcontractors at the base.The arrests Thursday culminated an 18-month investigation by the FBI and the Air Force Office of Special Investigations that began when other workers reported items missing from the base.

Mike Wilson, special agent-in-charge of the San Antonio FBI office, said undercover agents set up a bogus subcontracting company dubbed "Airprop Associates" to ferret out the loosely knit theft ring.

The stolen property sold to the fake subcontracting company included computer and electrical equipment, telephones, smoke detectors, jet engine parts and tools, Wilson said.

"They are independent operators that knew one another and occasionally did business together," Wilson said. "They were greedy enough to make use of our bogus operation. We were a conduit for stolen property."

Col. Robert Lukens said none of the stolen property was a threat to national security.

The charges were detailed in four separate indictments accusing the seven of unauthorized disposition of stolen property and conspiracy. The subcontractor was charged with conspiracy.

All suspects were released on personal recognizance bonds.

Conviction on the conspiracy charges carries a five-year prison sentence, while a theft conviction carries a penalty of 10 years.