MIAMI (AP) _ A former executive and two ex-mechanics for an aviation maintenance company pleaded innocent Thursday to federal charges stemming from the 1996 ValuJet crash that killed 110 people.

The mechanics, Mauro Valenzuela and Eugene Florence, and Daniel Gonzalez, SabreTech Inc.'s former vice president of maintenance, made their pleas before a federal magistrate judge. An attorney entered the same plea for the company.

The company and the men are charged with conspiracy and making false statements that led to the 1996 crash.

Investigators say SabreTech took oxygen canisters from another ValuJet plane, mislabeled them as empty, packed them up and delivered the carton to a ValuJet ramp, where it was loaded aboard Flight 592. Investigators said the canisters ignited in the cargo hold of the DC-9, transforming the jet into an airborne inferno that nose-dived into the Everglades.

This is believed to be the first time that criminal charges have been filed against maintenance workers in a U.S. plane crash. SabreTech also faces state charges of murder and manslaughter for illegally packaging the oxygen canisters, which also were missing required yellow safety caps.

U.S. Magistrate Judge Ted Banstra granted the defendants' request for a jury trial, which is scheduled to begin Nov. 15.

The three men remained free on bond. Each of them could be sentenced to up to 55 years in prison and fined $2.7 million if convicted.