Ms Murdoch, 28, joined BSkyB earlier this year, as general manager, broadcasting. She is to continue to oversee key operational aspects of the company's business, including its crucial subscription management centres in Scotland. But effective immediately, she will also oversee BSkyB's growing programming division.
The move follows confirmation last month that her brother Lachlan would become managing director of Mr Murdoch's Australian company, News Ltd, and will fuel speculation that he is grooming one or the other of the two children to take over from him when he retires.
Ms Murdoch, notoriously press-shy, began her television career in the US, with her father's company Fox. She bought and then ran two US local television stations, before coming to Britain to work for BSkyB.
Her appointment coincides with a restructuring of the company's programming operations. A new head of programming, James Baker, was also named yesterday, while Les Sampson, formerly programme manager at the Nine Network in Australia, is to become Controller of Sky Channels. Tim Riordan, director of broadcasting, remains in his position.
The changes were made necessary by the departure of David Elstein, formerly head of programmes, who is now chief executive of Channel 5 Broadcasting, backers of the new fifth terrestrial television service.
His direct replacement, Mr Baker, joins from Nickelodeon, the joint venture children's channel owned by BSkyB and Viacom, the US media giant. Mr Baker is expected to remain on the Nickelodeon board. Tensions have been growing between Viacom and BSkyB ever since Sky announced it would carry Mr Murdoch's Fox Kids, a competitor to Nickelodeon, in the UK market.
Mr Baker worked briefly for Sky in 1988, as entertainment producer at Sky News, and has had stints at TV-am, Channel 4 and GMTV.
Mr Sampson worked for Sam Chisholm, Sky's chief executive, when they were both at Nine Network, Kerry Packer's television company in Australia.