Futures exchange group Intercontinental Exchange Inc. said it agreed to buy Climate Exchange for 395 million pounds ($606.7 million) to create a single trading platform for environmental contracts worldwide. Shareholders in Climate Exchange, the operator of the European, Chicago and Chicago Futures carbon emissions exchanges, will receive 750 pence a share in cash, representing a 57 percent premium on Thursday's closing price, ICE said in a statement on Friday. Climate Exchange was founded by Richard Sandor, a longtime futures industry executive in Chicago.