The BBC's director of communications Ed Williams will leave the corporation in October to join Edelman as UK CEO.
Williams will report to Edelman’s EMEA CEO Robert Phillips, and join the Edelman EMEA leadership Team.
He said: ‘It has been a great privilege to serve Mark Thompson and the BBC, one of the world's greatest and most valuable cultural institutions.
"Despite the daily rough and tumble in the press, I am pleased that over the past few years public support and approval for the BBC has reached historic highs."
BBC director general Mark Thompson commented: "Always strategic, always calm in a crisis, Ed has been a brilliant director of communications for the BBC. I am very grateful for everything he has done for the BBC and for me over the past few years and wish him every success in the future."
Williams joined the BBC as director of comms in 2008, having been director of comms at Reuters and then a director at Brunswick for five years. He started his career in journalism, spending four years as news editor of GMTV.
He currently oversees around 160 comms staff. Following last year’s review, all staff are based in one division.
In March, the BBC abolished six senior comms roles as part of a programme to make cuts of 25%.
PR Weekly said BBC sources indicated that the corporation will seek an internal replacement for Williams.