The US airline criticised the verdict as "absurd" and confirmed it would appeal. It said the court ruling was aimed at shifting blame away from Air France and French aviation authorities.
Nobody was jailed over the disaster, in which the New York-bound plane smashed into a hotel after take-off from Paris' Charles de Gaulle Airport on 25 July, 2000, killing 109 people on board and four people on the ground.
French prosecutors claimed the Concorde was brought down by a piece of metal that had fallen off a Continental DC-10 aircraft and onto the runway, which burst a tyre on the Concorde.
This in turn hurled debris into the fuel tank, causing a fire.
The judge gave Continental employee John Taylor a 15-month suspended jail sentence for having incorrectly manufactured and installed the metal strip.
His supervisor Stanley Ford, who stood accused of approving Taylor's work without checking it, was acquitted, as were three French aviation officials.
Among them was the former head of the Concorde programme, 81-year-old Henri Perrier.
Continental had denied that the metal strip triggered the disaster by shredding the Concorde's tyre, with lawyer Olivier Metzner insisting the supersonic jet had already been on fire for 700 metres of runway.
“(The judgment) is far away from the truth, from rights and from justice,” said Metzner.
“They have preferred to give privileges to purely national interest, while respecting the icon that the Concorde represents,” said Metzner, who added that the US airline would appeal the verdict.
He maintained throughout the four-month trial hearings, which ended in May, that the maintenance by Concorde operator Air France was negligent and that the plane should never have been allowed to fly.