General Electric has sealed its $17 billion purchase of Alstom's energy assets in what will be its biggest acquisition to date upon completion. As part of the agreement, the companies will create three energy joint ventures and combine their rail-signaling units. The deal follows the French government's decision to back General Electric's bid after agreeing to buy a 20% stake in Alstom from shareholder Bouygues. The Deal correspondent Paul Whitfield explains the details of the deal and what it will mean to the company. Whitfield also sheds light on whether Alstom is likely to be happy with the deal in the long run, as concessions were made to appease the French government.