News Corporation faces a potential “deadlock” once Rupert Murdoch’s heirs take over, according to a biography of the 77-year-old media owner whose empire stretches from the Sun newspaper in London to Star TV in Asia.

An agreement giving equal economic rights in the Murdoch family’s stake in the company to all six of its chairman’s children – but voting control to the eldest four only – contains no provision for breaking tied votes, the book reports.