Writtle Holdings has sold Speed to Mission Marketing Group, which owns integrated agency Bray Leino, for an undisclosed sum.
Speed employs 25 people and works with adidas, GSK and Lucozade Sport, as well as The Economist and The Financial Times. Bray Leino's PR operation employs 40 staff and its clients include Virgin Media, Samsung, RAC and Remington.
According to PRWeek's latest Top 150 Agencies report, Bray Leino generated PR fee income of £2.1m with revenue of £2.7m in 2013. Speed Communications did not take part; however, in the 2012 Top 150 Agencies report it disclosed fee income of £1.7m for 2011, down 8 per cent from the previous year, and put its staff numbers at 33.
The merger is set to take legal effect on 1 January 2015. Roberta Fuke, the MD of Bray Leino's PR operation, will become chief executive and deputy chairman, while Will Whitehorn, who has worked with Bosomworth and the Speed team for the three years, will become non-executive chairman.
Kate Bosomworth of Speed, Alison Weir and Kelly Pepworth of Bray Leino will be managing partners.
Bosomworth will concentrate on sport and media clients and manage its London office while Pepworth will handle business and corporate work and manage the Bristol office.
"Speed and Bray Leino individually have extremely impressive track records of success," said Fuke. "By combining the talents of the teams the opportunity to create a major new force in the PR industry is significant.
"Combine that with the fact that the culture, approach and ambitions of each consultancy are amazingly similar and it made the decision to merge the two businesses one of the simplest decisions we’ve ever had to make."