LONDON—Tonic Life founders Scott Clark, Oliver Parsons and Moira Gitsham are to depart the agency five years after its sale to Huntsworth Health.

The trio, together with Tonic Life London MD Stéphanie Bunten, will leave over the coming months. 

Founded in 2004, Tonic Life sold to Huntsworth Health in 2009. In the same year, the firm was merged with Dorland Global PR to double Tonic’s size and reach and create a global PR agency The earn out for the Tonic founders ended in July 2013.

Group CEO Clark and group MD Parsons will remain with the agency until 2015 to oversee the management transition. A search for a new group CEO and other senior roles is underway.

Tamsin Tierney, deputy MD in London, will continue to work closely with Maryellen Royle, president of Tonic North America. Annabelle Sandeman, VP of strategic development at Huntsworth Health, will support the London operation.

“We are very proud of all that we have accomplished at Tonic and honoured to have worked with the very best people in the business over the last decade,” said Clark.