The rupee weakened to 64.03 due to month-end dollar demand from importers and banks.

According to forex dealers, month-end demand for the US currency from importers and a weak domestic equity market put pressure on the rupee. However, a weak dollar overseas provided some cushion to the domestic currency.

The domestic unit opened weak by 4 paise at 63.95 at the Interbank Foreign Exchange market today. It hovered in a range of 64.03 and 63.92 before quoting at 64.02, down 11 paise at 3.55 pm local time.

Yesterday, the rupee had rallied by 13 paise to end at a near three-week high of 63.91 a dollar on account of heavy selling of the US currency by exporters and banks.

The euro surged past a key level on Tuesday as investors grew bullish about its outlook after the head of the European Central Bank refrained from talking about the single currency's recent strength and in the backdrop of brewing US fiscal problems.

The single currency was up 0.4 per cent in early trades to $1.2029 against the dollar, up nearly 1.5 per cent so far this month. It is the best performing currency in the G10 FX universe.

Meanwhile, the benchmark BSE Sensex ended the session down by 362.43 points or 1.14 per cent at 31,388.39.