New York Mercantile Exchange, the world's largest energy futures market, has confirmed it is willing to talk mergers amid speculation that it has made a $300m (€247m) to $350m offer for Atlanta-based IntercontinentalExchange, owner of the International Petroleum Exchange in London.

A New York Mercantile Exchange spokesman said: "We are open to any kind of relationship or alliance with institutions or exchanges with whom we have synergies, and IntercontinentalExchange would obviously be a candidate, but we will neither confirm nor deny a specific offer."