Lowe said it was unwilling to compromise its creative principles to keep the account, and admitted its decision will result in some job losses.
Sources close to Braun said Lowe's withdrawal had left the way clear for BBDO, which is globally aligned with Gillette and already handles Braun's Oral B dental range. The business is likely to be led out of London by Abbott Mead Vickers BBDO.
Braun will be a serious loss for Lowe, whose HSBC client confirmed a review of its global business earlier this month.
Lowe's problems have been compounded by news that Verizon is reviewing the creative assignment on its account out of Lowe New York. In a rallying memo to all staff, Jerry Judge, the Lowe Worldwide chief executive, called Verizon "a sad and, in my eyes, unjustified loss". He added: "If anybody asks you about the strength of your company, tell them adversity makes us stronger than ever."