BBC executive Jana Bennett is to leave her role as director of vision to take a new role in the BBC's commercial arm.
Bennett, who has held her present post since 2006, is the latest senior figure to announce their departure.
She will take up a newly created role at BBC Worldwide as president, worldwide networks and global iPlayer, in February.
Bennett is one of the most powerful figures in broadcasting, overseeing a budget in excess of £800 million and looking after six TV channels.
Major hits which she has helped to drive have been Strictly Come Dancing, the revived Doctor Who and turning Top Gear into a global brand.
Other executives to announce their exit from the corporation in recent months have included deputy director general Mark Byford and marketing chief Sharon Baylay.
BBC1 controller Jay Hunt has also moved to Channel 4 - quickly replaced by BBC3's Danny Cohen - and the BBC Trust chairman Sir Michael Lyons has said he does not want to serve a second term.
Bennett, whose previous roles have included director of television, will be in charge of driving international growth for Worldwide's channel.
She will also be responsible for the global iPlayer, which will deliver British TV content around the world. It will be piloted in the first half of next year.
John Smith, CEO of BBC Worldwide, said: "Jana's track record in commissioning and producing world-class content across the whole spectrum of genres is second to none.
"I am delighted she is joining us in a role where her editorial skills, her understanding of what the BBC means and her knowledge of launching and running successful channels will be harnessed globally."
BBC director general Mark Thompson said: "Jana has been an outstanding creative leader of the BBC and a very supportive executive colleague.
"Her understanding of what makes great television and what audiences want has led to a sustained period of creative success, and she is just the person to take our international channels to the next level and oversee the creation of a successful Global iPlayer."
Bennett, who receives a £415,000 salary as director of vision, said: "I always said it would take something pretty special to get me to consider another job in broadcasting.
"The chance to manage and grow BBC Worldwide's portfolio of channels was just that challenge. And when you add in the possibilities we have with the Global iPlayer it was something that I knew I just had to do."