The Court of Appeal has thrown out the latest attempt to trademark the shape of London's traditional black cabs.
It has upheld a decision by the High Court in 2016 that the shape lacked "distinctive character" and was not a "valid registered trademark".
The London Taxi Company, which makes traditional hackney carriages, had taken rival firm Frazer-Nash to the High Court last year.
It argued the design of Frazer-Nash's Metrocab was "substantially copied".
However, last year's ruling by High Court judge Mr Justice Arnold was upheld by Lord Justice Kitchin and Lord Justice Floyd at the Court of Appeal.
The London Taxi Company has indicated that it may take the case to the Supreme Court.
Metrocab said it was "delighted" at the ruling, while the London Taxi Company declined to comment on the decision.