Updated

A French magistrate on Thursday formally placed Continental Airlines (search) under investigation for the suspected role played by one of the U.S. carrier's jets in the crash of the supersonic Concorde (search) in July 2000.

It was the first time that French judicial authorities have formally opened a case in the Concorde crash that killed 113 people. Two probes by experts — including one by the prosecutors' office — pointed to a titanium strip from a Continental jet as the source of the disaster.

French investigating judge Christophe Regnard placed Continental under investigation — a step short of being formally charged — for manslaughter and involuntary injury, judicial officials said.

The Houston-based carrier expressed confidence that it would be exonerated.

"Continental Airlines was placed under investigation by the magistrate in today's hearing, but it is important to note that this is just the beginning of the investigation part of the proceeding," the company said. "We are confident that the evidence will ultimately show that Continental was not responsible for this tragic accident."

The two investigations, one by France's (search) accident office and the other ordered by the prosecutors' office, concluded that a titanium "wear strip" that fell from a Continental DC-10 onto the runway caused a Concorde tire to burst, propelling rubber debris that perforated the supersonic plane's fuel tanks.

However, the judicial inquiry, made public Dec. 14, also determined that the Concorde's fuel tanks lacked sufficient protection from shock — a risk known since 1979.

The investigating judge met Thursday with a legal representative of the carrier before formally placing the airline itself under investigation. The official, not identified by name, served as the representative of the airline for the French procedure.

Depending on the outcome of the formal investigation, charges can be dropped or the airline forced to answer in court.

Judicial officials, asking not to be named, said that the judge would summon technical representatives of the carrier in April.

On Tuesday, Judge Regnard questioned Continental vice president Ken Burt, in charge of technical direction, for more than seven hours.

"Continental Airlines committed no fault," said attorney Olivier Metzner, who accompanied the airline's officials in their appearances before the judge.

The lawyer said that aeronautic authorities in the United States conducted their own inquiry "and concluded that Continental Airlines committed no fault whatsoever in the crash of the Concorde," Metzner said.

"Are French authorities not more protective of what was considered a jewel of France, the Concorde?" he asked rhetorically.

The Concorde exploded in flames two minutes after takeoff from Charles de Gaulle airport on July 25, 2000, and slammed into a hotel, killing all 109 people on board and four on the ground. The crash spelled an end to the career of the sleek but costly supersonic aircraft run by Air France and British Airways.

The prosecutor's office has contended that Continental violated U.S. Federal Aviation Administration rules by using titanium in a part of the plane that normally called for use of aluminum, which is softer.

However, the judicial report also cited weaknesses in "the training and preparation of the Concorde teams," and insufficient protection of the supersonic jet's tanks.

Experts pointed to 67 cases of tire or wheel ruptures which in 24 cases "provoked one or more impacts on the structure," the report said. It added that in seven of the incidents "the fuel tanks were pierced with one or more holes."

Continental Airlines shares fell 35 cents, or 2.9 percent, to close at $11.65 in Thursday trading. The stock has been trading at a 52-week range of $7.63 to $14.38.