LONDON, July 10 (Reuters) - Some of the world's biggest carmakers on Friday broadly won the first stage of a mammoth legal battle over whether some of their diesel vehicles contained prohibited "defeat devices" which limited emissions control systems.

Judge Sara Cockerill said in a summary of her ruling that she had "rejected most of the principal allegations advanced against the manufacturers whose vehicles were examined at trial", though she said she had made some adverse findings.

The ruling followed a trial which focused on 20 sample vehicles produced by five manufacturers: Mercedes-Benz MBGn.DE, Ford F.N, Nissan 7201.T, Renault RENA.PA and the Stellantis-owned STLAM.MI brands Peugeot and Citroen.