NYSE Euronext has appointed Demetria O'Sullivan as chief risk officer of its new derivatives clearing house in London, NYSE Clearing. NYSE Clearing intends to launch a revamped platform in June 2013 to expand its existing clearing business. O'Sullivan will report to Mark Ibbotson, chief executive of NYSE Liffe for clearing, trading and regulation. O'Sullivan will join NYSE Euronext on 3 December, having worked most recently at Citigroup where she had been global head of risk futures and OTC cl