NYSE Euronext, the shares and futures exchanges group, saw its profits plunge 44 per cent in the first three months of this year as its was hit by the costs of its blocked merger with Deutsche Börse and lower trading volumes in the US.
Post-tax profits dropped to $87m (£53m) from $155m, lower than most analysts had forecast.
Earlier this month, NYSE Euronext told investors it would make savings of $250m a year by 2014 as exchanges worldwide react to lower equity trading volumes.
Duncan Niederauer, the chief executive, said: "Our first-quarter results reflect the challenging operating environment which carried over into 2012 and will continue to result in near-term headwinds."
NYSE Euronext said the volume of shares traded on its US exchanges was 23 per cent lower than a year ago at 1.18 billion a day. In Europe, the daily average slipped from 1.8 million to 1.6 million.
The European Commission blocked the Deutsche Börse merger in February on the grounds that it would create "a near monopoly in European derivatives trading".