LONDON—Steffan Williams has left Finsbury to join Porta Communications in the newly-created role of group managing director.

Williams, who reports to Porta CEO David Wright, is charged with leading the next stage of Porta's growth "including recruiting the best available talent and improving the ratio of larger client mandate wins."

Porta, which owns a range of communications firms, including Newgate, Publicasity, Redleaf and Thirteen, recently reported a 75% increase in revenues for the first six months of the year.

Williams joined Finsbury as a partner in 2014, departing Capital MSL, the agency he co-founded in 2001.

I have always had a very high opinion regarding Steffan’s qualities and this appointment is a great start to an exciting period of development at Porta," said Wright in a statement.