The agency confirmed that Foulkes, who has been with Imagination for nearly 30 years, is leaving to pursue other opportunities.
Foulkes told C&IT: "It has been a pleasure be part of an inspirational company like Imagination for so many years. But now the time feels right to spread my wings and work with some of the other great people in the industry, to be re-inspired, reinvigorated and re-invented. Now is a time for reflection, then planning, then action. How exciting. Lets see what unfolds, and unfold it will."
His out of office message states: "After nearly 30 years with this great company, due to a restructure, from 31st August I will be branching out on my own."
There are currently no further details available about the restructure and Imagination's CEO is unavailable for comment. A statement from the company said Foulkes "has recognised a number of opportunities outside Imagination that he would like to pursue. We are extremely grateful for the nearly 30 years contribution Richard has made to Imagination across many aspects of our business and many different clients."
Foulkes is a prominent figure in the events industry, having held the position of president for the ISES UK chapter from 2010 to 2011. Last year, he became the first UK president and non-American to be appointed to the ISES international board of governors, based in Chicago.