Williams (pictured) told PRWeek: "I went to Portland to set up a financial comms practice for them. I feel that's gone very well – they've won some prestigious clients in that time, including Coca-Cola European Partners, AstraZeneca and Robert Walters. Now it's time for me to do something else."
He declined to reveal more about his new venture.
Before Williams' arrival, Portland – founded in 2001 by former Tony Blair comms chief and ex-Sky director of comms Tim Allan – had primarily focused on corporate comms and public affairs, although it had undertaken some financial PR work for clients.
Portland chief executive Mark Flanagan said: “I’m extremely grateful to Steffan for helping us establish a successful financial communications practice and put our name on the map in that part of the market. He has been a great colleague to work with, we thank him for the contribution he has made and wish him well for the future.”
Williams, an experienced financial comms figure, founded Capital MSL in 2001 before its 2013 sale to Publicis. He was previously a partner at Finsbury and chief executive of Porta Communications. Williams is also a former chairman of the PRCA.
In July, PRWeek revealed that Portland is to restructure most of its global business under a single P&L, with a new MD – Sam Ingleby – appointed to the combined operation and the announcement of several senior departures.