Borse Dubai is set to emerge as the biggest shareholder in two of the three largest stock exchange groups in the world barely a month after it was set up, after striking a complex deal with US group Nasdaq, its rival in the battle for control of Nordic exchange OMX.

Under the terms of the deal, which Nasdaq announced this morning in a statement to the UK stock market, the US exchange will abandon the recommended takeover bid for OMX it launched in May, paving the way for Borse Dubai, which already controls more than a quarter of OMX's shares after swooping with a rival offer last month, to seal the transaction.