The terms of the purchase will see Climate Exchange, which owns the European Climate Exchange and its Chicago counterpart, valued at approximately £395m.
Shareholders at the London-based firm are set to receive £7.50 per share.
It is thought the deal will be finalised by the end of July, subject to the satisfaction of conditions.
Jeffrey Sprecher, chairman of ICE, which is the second-largest US futures exchange, was delighted.
He
