The Haas F1 Team failed to win its appeal against the Italian Grand Prix stewards' decision to exclude Romain Grosjean from the results of last September's race.
The French driver had finished sixth at Monza but was subsequently disqualified following a protest to the stewards lodged by the rival Renault squad.
The bone of contention, as Renault saw it, was related to the legality of the front edge of the floor on Grosjean's VF-18, which stipulated the need for a 50mm radius.
After the Monza race, the Haas floor was found not to comply with Article 3.7.1.d of the sport's technical regulations.
On Friday morning in Paris, after hearing from representatives and witnesses for Haas, Renault and the FIA, the International Court of Appeal upheld the stewards’ decision to disqualify Haas F1 Team from the race.
"Haas’s car was in clear breach of the Technical Regulations and was sanctioned by the stewards appropriately," said Renault.
"Technical Regulations - especially those introduced for safety reasons - must be observed strictly," added chassis technical director Nick Chester.
"We are satisfied with the decision and I would like to thank the court and the FIA for their work on this matter. The team is now focused on the end of the season."
The FIA's decision preserves Renault's 30-point advantage over Haas in the Constructors' standings, with the French outfit currently sitting fourth and 'best of the rest' among the teams.
"Obviously we are disappointed not to have won our appeal," commented Haas team boss Guenther Steiner.
"We simply move forward and look to the final two races of the year to continue to fight on track, earn more points, and conclude our strongest season to-date in Formula 1."