ROCHESTER, N.Y. (AP) _ Charges against a father and son suspected in the nation's largest armored car robbery were dropped hours after they were filed because of ''inconsistencies'' in the arrest warrant, federal officials said.

Albert Michael Ranieri, the driver of the armored truck robbed of $10.8 million in June 1990, and his father, Albert Bruno Ranieri, were arrested Wednesday and charged with bank robbery.

A few hours later, the Ranieris were supposed to be arraigned before U.S. Magistrate Kenneth Fisher. But federal officials abruptly asked that the charges be dismissed and the information in the warrant be sealed.

FBI spokesman Paul Moskal said the FBI had discovered inconsistencies in information provided to them. Assistant U.S. attorney Christopher Taffe said the government wants the information sealed because it is concerned for its informant's safety and because the investigation is continuing.

Fisher gave the government until noon Friday to show why the information should be sealed.

Moskal and Taffe refused to give details on their request. The Ranieris also refused to comment.

The AMSA truck was robbed on June 26, 1990, when Ranieri and a female guard stopped at a convenience store for sandwiches and coffee. The two employees told the FBI they had been held at gunpoint by masked robbers. None of the money has been recovered.

Two federal grand juries have investigated the Ranieris in connection with the armored car heist but did not indict them.