Greifeld says his plan to purchase NYSE Euronext offers $US300 million more in cost savings than Deutsche Boerse's proposal. Nasdaq OMX, the second-largest US bourse operator, and ICE say they will generate about $US740 million in expense cuts and synergies in three years. Nasdaq OMX had been left out of exchange mergers since October, when Singapore Exchange offered $8.35 billion for Sydney-based ASX Ltd. In addition to the Deutsche Boerse offer in February, London Stock Exchange Group Plc said that month that it would buy Canada's TMX Group.