US exchange operators shares fell after politicians said last night they would propose a tax on financial transactions such as stock and bond trades.

NYSE Euronext fell 6.8 per cent, while Nasdaq OMX was down 2.8 percent. CME Group slumped 8.6 per cent.

The proposals will give the US an increased role in the international debate over a transaction tax, which is likely to be discussed at the G20 summit this week in Cannes. The U.S. tax would be about 0.03 per cent. – (Bloomberg)