Steel said: ‘It's been an enormous privilege to have been at the centre of some of the biggest media stories of the past decade, and to have been entrusted with the role of protecting and enhancing the BBC's reputation.’
BBC head of media Paul Mylrea will continue to handle the media relations role once Steel has gone.
Steel spent 11 years as the BBC's chief media spokesman, after working as a local radio producer and presenter. His first PR role was as publicist for The Archers.
During his tenure at the BBC, Steel has handled stories such as the murder of presenter Jill Dando and the terrorist bomb attack on Television Centre in 2001.