PARIS – French judges filed preliminary charges Wednesday against former Airbus CEO Gustav Humbert as part of an investigation into alleged insider trading, a judicial official said.

Humbert is the third former executive at Airbus or its parent company, EADS, to face charges in the investigation.

Two judges filed the charges then released Humbert on a bail of 350,000 euros ($553,000), said the official, who was not authorized to be named publicly about such matters.

Humbert had been in detention since Monday, and remains under judicial supervision, the official said.

Preliminary charges under French law mean investigating magistrates have determined there is strong evidence to suggest involvement in a crime. The filing gives the judges time to pursue an investigation that can result in a trial or in the charges being dropped.

The judges are looking into stock trades at EADS in 2005 and 2006. Humbert and other top executives sold large share packages before delays to the superjumbo A380 were announced, delays that sent the EADS share price plunging.

Humbert, 58, was chief executive of Airbus from June 2005 to July 2006. He quit soon after the announcement of the delays.

Noel Forgeard, former co-CEO of European Aeronautic Defence & Space Co. NV, and Jean-Paul Gut, a former deputy chief executive who oversaw strategy for Airbus' parent, also face preliminary charges in the investigation.