Sambrook will spend more time working as a visiting fellow at the Reuters Institute for the Study of Journalism in Oxford, before taking up a new role outside of journalism and broadcasting.
"I
have enjoyed fantastic opportunities as a producer and editor,
witnessing moments of history, meeting the powerful and the powerless
and touching the lives of millions through landmark programmes," he wrote.
"It has been a joy to work with hugely talented teams and
individuals across the BBC and in particular in the last few years in
the World Service and Global News. Their commitment to strong,
impartial, independent news, which I've been proud to support, develop
and defend, remains as important today as it has ever been."
His departure date will mark 30 years in journalism, added Sambrook, who has also led the BBC's sport and news divisions.
Peter Horrocks, currently director of the World Service, will succeed Sambrook as director of global news. The BBC plan to combine the two roles, making Horrocks responsible for all the BBC’s international news services.
It was reported last year, following the departure of Nigel Chapman, that the role of director of the World Service was being kept open for Sambrook, then news director at the BBC, and not properly advertised outside of the organisation. Sambrook denied these claims however, and the position was filled by Horrocks, head of the BBC's multimedia newsroom.
"It has been a privilege to lead three different divisions of the BBC and to have played a part in the huge changes in news broadcasting over recent years" said Sambrook, on announcing his departure.
"The BBC is never an easy organisation to leave, but this feels like the right time for me to take a new direction. I will continue to take a close professional interest in global affairs and digital communications – first at the Reuters Institute and then in a new role elsewhere to be announced next year."