The 42-strong team, which joined Orrick’s Paris office in October 2002, demanded €290,000 (£196,900) in lieu of unused holiday under French employment law.
Watson Farley rejected the demand and retaliated by issuing a claim against all of Orrick’s Paris partners seeking a declaration that the firm was not liable for such a payment.
Orrick Europe managing partner David Syed, who was part of the team that left, said: “From our standpoint we find it quite humorous.”
Michael Greville, Watson Farley’s managing partner, said Orrick’s demand was “nonsense” and argued that when the Paris team left, the US firm assumed responsibility of the former employees.
Orrick did not file a defence to the UK High Court proceedings launched by Watson Farley, so a declaration was made last month in favour of the City firm.