WPP has merged the UK arms of Possible and Mirum, appointing Possible UK group boss Chris Daplyn to lead the consolidated agency.
The Possible UK brand will be sunsetted as part of the move, with both businesses united under the name Mirum UK as one "digital experience and innovation agency".
The new entity will be a standalone brand within the Wunderman Thompson network.
Wunderman Thompson said Mirum UK managing director Antti Lauronen is "leaving the company to pursue other opportunities".
The full Mirum UK leadership team will be announced within the next few months and the newly formed Mirum UK will co-locate in June 2019.
Globally, Possible will continue to operate within the Wunderman Thompson network.