In a filing with the Securities and Exchange Commission on Thursday the company said Murdoch bought the Class A nonvoting shares on Feb. 8 at an average price of $16.81 each.
The CEO's purchase is "a sign of his belief in the future of the company," said News Corp. spokeswoman Teri Everett.
News Corp. did better than Wall Street expected in the most recent quarter, helped by higher advertising revenue and a growing subscriber base for the company's cable channels.
The New York-based company, which also owns The Wall Street Journal, recently launched the world's first iPad-only newspaper. It plans to charge 99 cents per week or $40 per year for the publication, called The Daily.
The Murdoch Family Trust owns about 40 percent of the media conglomerate's Class B voting shares, but less than one percent of the Class A shares, according to FactSet data. The stock closed Thursday down 15 cents at $16.76.