McGraw-Hill Cos. and CME Group Inc. said a joint venture to combine index businesses started today with the creation of S&P Dow Jones Indices. CME Group, the world's largest futures exchange, in 2010 agreed to take control of News Corp.'s stock-index business, owner of the Dow Jones Industrial Average, to bolster revenue by licensing equity benchmarks. The new business publishes indexes for 575 exchange-traded funds with $387 billion in assets and benchmarks that comprise $1.5 trillion, the companies said today in a statement.