Fetch founder and chief executive James Connelly is exiting the business he sold to Dentsu Aegis Network (DAN) for £30m in 2014 to take a "gap year" from the industry.
Connelly first set up mobile agency Fetch in his kitchen a decade ago before selling up to the network when the business turned five.
Under DAN's watch, Fetch has expanded into APAC. It counts Very, The Telegraph, AEG and eBay as clients.
Despite its success, the agency found itself in the eye of a storm in 2017 after former client Uber alleged it had misrepresented how effective its media buys were. The ride-sharing service also accused it of purchasing nonexistent and fraudulent ads.
Fetch denied the claims, then retaliated by counter-suing Uber for around $20m over unpaid invoices.
In the years since DAN's acquisition, Connelly has continued to head up the business as chief executive. Last year, he was appointed to the role of chief strategic development officer for DAN – in addition to his role as chairman - tasked with heading up the UK M&A strategy and new routes to market.
Writing in a LinkedIn post, Connelly explained how 2019 marked 10 years since Fetch started trading and said he saw it as an opportunity to think about "what's next".
"To that effect, I have decided to step down from both Fetch and Dentsu Aegis Network, this will be my last week," he added.
"I’d like to thank everyone at Dentsu for supporting me, for welcoming us into the network and giving me the opportunity to work with many truly amazing people. Having spent the last 12 months working on the DAN corporate strategy, I can see how special Dentsu and DAN is.
"Businesses that have a clear vision but also the capability to adapt will win in this period of change, putting both Fetch and Dentsu Aegis Network in a strong position."
Connelly said he'd spend 2019 taking the "gap year" he never "quite got around to".
DAN hasn't given any indication on how it plans to fill his roles. However, in a statement, the group's executive chairman, Nick Waters, said: "Not only has James integrated a brilliant agency into our network in Fetch, he has played a key role in the development of our corporate strategy for the years ahead.
"We will miss James’s energy and passion, but we respect his decision and wish him all the best for the future."