Dawn Airey, one of the most senior women in British television, is to step down as an executive at BSkyB after four years.
Ms Airey, 46, will remain at the company until spring next year, when she will join the recently launched rights and distribution company Iostar as chief executive.
"Dawn has made a significant contribution to Sky's appeal," James Murdoch, the BSkyB chief executive, said last night. "She has been a valued colleague and a trusted friend."
Ms Airey joined the broadcaster from Channel Five in January 2003 and is managing director of channels and services.
Iostar had been looking for a high-profile executive to head up its interests, which will range from factual and entertainment, to films, management and international distribution.
Ms Airey has made no secret that she had itchy feet after four years at BSkyB. In a newspaper interview last month, she said: "I don't know what I'm going to do next. It will be in the creative industries and it may well be something that surprises everyone in the way coming here did."
Born in Lancashire and educated at Girton College, Cambridge, Ms Airey lived for 19 years with a publisher, Martin Pearce, before meeting her current partner, Jacquie Lawrence.