Nasdaq, the US high-growth stock exchange, warned that its market share could by hit hard by the arrival of added competition including Archipelago, a new rival exchange, as it reported a 64% dip in profits.

Nasdaq is facing increased competition in two of its main revenue areas, market information services and transaction services. Archipelago, which is being set up by the Pacific Stock Exchange, received approval from the US Securities and Exchange Commission last month, while Island ECN, an alternative trading platform, has applied for exchange registration.