Wick Simmons, chairman and chief executive of Nasdaq, confirmed that the US exchange is on the hunt for acquisition targets but is not for sale itself, as it reported a small increase in profits.

Simmons said: "We are talking to a number of players in our business now. In these sorts of market conditions scale makes a considerable difference. The emphasis is to buy and build. We have a wonderful business model and we will add to it if we can."