Uber's London-based head of northern Europe affairs is leaving the company as the ride-hailing app fights to have its London licence renewed.
In an email to staff, Jo Bertram said: "I've decided to move on to something new and exciting."
Uber says her departure is not connected with recent events.
The company's London licence expired on Saturday after it was deemed "unfit" to run a taxi service.
Uber's drivers can continue to operate in the capital while the firm pursues an appeal against the decision from the regulator, Transport for London (TfL).
Uber chief executive Dara Khosrowshahi is due to meet TfL commissioner Mike Brown on Tuesday for talks.
TfL was critical of Uber's record over reporting criminal offences and carrying out driver background checks.
Ms Bertram has been with the company for four years and oversaw its major expansion in London.
Sources at the firm insist she had been planning to leave for a new role at another organisation for a while.
In her email, Ms Bertram says: "Given some of our current challenges, I'm also convinced that now is the right time to have a change of face, and to hand over to someone who will be here for the long haul and take us into the next phase."
Uber is used by an estimated 40,000 drivers and 3.5 million customers in London.
Last month, TfL said it would strip the firm of its licence to operate in the city. It pointed to Uber's approach to reporting serious criminal offences, obtaining medical certificates and background checks into drivers.
Uber said it had followed the regulator's rules and worked closely with the Metropolitan Police.
However, it has apologised for "mistakes" and said it could make concessions to be allowed to stay.
More than 680,000 people have signed an online petition calling for Uber's licence to be extended.