News Corp's Dow Jones & Co Inc is only in the early stages of exploring a sale of its stock market index business and a sales prospectus has not gone out yet, a source familiar with the matter said.

Goldman Sachs has been hired as a financial advisor to explore the options for the business, which includes the Dow Jones industrial average <.DJI>, according the source, who declined to identified because the process is private.

A Dow Jones spokesman could not be reached immediately for comment.

Rupert Murdoch's News Corp bought Dow Jones in 2007 for $5.7 billion, but since then he has come under criticism for paying such a hefty price for a publishing company whose businesses have suffered from the sharp drop in ad sales. Earlier this year, News Corp wrote down $2.8 billion in Dow Jones' value.

The move to explore options for the business is not surprising. Industry analysts never felt it was much favored by Murdoch, a passionate backer of newspapers and one of the best-known media moguls.

Indeed, a number of analysts expected him to consider a sale of the index business soon after striking the deal for Dow Jones.

Potential buyers for the business could include McGraw-Hill Cos Standard & Poor's, Russell Indexes, MSCI Inc , Bloomberg, Pearson Plc's
Financial Times and Thomson Reuters Corp . On Friday, all of those companies declined to comment.

The Wall Street Journal, which first reported the news, said the process could result in an arrangement other than a sale, like a joint venture.

(Reporting by Jui Chakravorty; Additional reporting by Megan Davies; Writing by Paritosh Bansal; Editing by Diane Craft)