They had been charged with contributing to the deaths of Diana, her companion Dodi al-Fayed and the driver by chasing the car and failing to help the victims.
A Paris judge last year accepted the investigating magistrates' recommendations to blame limousine driver Henri Paul and clear 10 paparazzi.
They had been charged with contributing to the deaths of Diana, her companion Dodi al-Fayed and the driver by chasing the car and failing to help the victims.
Diana died when her limousine smashed into a pillar in a central Paris underpass on 31 August 1997.
Egyptian-born businessman Mohamed al-Fayed and Henri Paul's family insist that the pursuing pack of photographers forced the driver to speed through Paris and should therefore bear some of the blame.
Recommendations
The state prosecutor recommended at the closed door appeals court hearing last month that the appeal should be rejected and that Henri Paul should bear the blame, after being found to be drunk and under the influence of anti-depressants at the time of the high-speed crash.
But Tuesday's ruling by no means spells the end to marathon legal proceedings over Princess Diana's death.
Mr al-Fayed may still appeal to France's supreme court to have the original ruling annulled on a technicality.
He argues that the two magistrates who investigated the accident committed a procedural error by both signing their final conclusion.
Normally only the chief investigator should have done so.
He is also suing the French Government for what he alleges was a failure to investigate the crash properly.
The Harrods boss is convinced that "evil and racist forces" working through Britain's security service killed Diana and Dodi.
He also has said he will file a lawsuit against US authorities to release documents he says may prove the couple were murdered.