The two remaining partners and six assistants in Wilde Sapte's Paris office are understood to be joining the 45-lawyer Paris office of US firm Wilkie Farr & Gallagher.
Richard Macklin and Olivier Tordjman had spent several months deciding whether to stay at the firm or follow asset finance partner Thomas McDonald's lead and join up with a rival firm.
McDonald will join the Paris office of US firm White & Case after he has agreed with Wilde Sapte the length of his gardening leave.
It is unclear whether Macklin or Tordjman will be held to similar notice periods – understood to be two and half years for partners.
The exodus leaves Wilde Sapte with a skeleton staff in Paris, but a spokesperson for the firm said there were no plans to close the office.
He admitted that the loss of the partners was a severe blow, but insisted that the firm planned to rebuild its Paris-based practice by sending out London-based partners and recruiting French lawyers.
Wilkie Farr & Gallagher has a mainly French law driven corporate finance, litigation and tax practice in Paris. It would not confirm the move.