Awwal 24, 1432 / April 28, 2011, SPA -- The dollar slumped to a three-year low Thursday as the euro nudged towards the key 1.50-dollar mark after the US monetary authorities left interest rates on hold, as dpa reported. The move by the US Federal Reserve to leave rates at between zero and 0.25 per cent as well signalling it was winding back its bond-buying programme in June came less than a month after the European Central Bank delivered its first hike in borrowing costs in three years. While markets are expecting the ECB to follow up this month's 25-basis-point increase with further rises in the coming months, the Fed is projected to keep the cost of money on hold after downgrading its growth outlook for the US economy. Analysts believe the next ECB rate in borrowing costs could come as early as June or July after the Frankfurt-based raised its benchmark refinancing rate from an historic low of 1 per cent to 1.25 per cent at its April meeting. As the European trading day got underway, the euro was hovering just short of 1.49 dollars.