The rupee weakened by 9 paise to trade at 63.67 against the US dollar in opening session at the interbank foreign exchange on Tuesday amid the dollar’s gains in global markets.

Forex dealers said increased month-end demand from banks and importers and a weak opening in the domestic equity markets weighed on the domestic unit.

On Monday, the rupee had ended lower by 3 paise at 63.58, halting its three-day rally even as the Economic Survey printed a rosy picture of India’s macroeconomic outlook.

Meanwhile, the benchmark BSE Sensex was trading lower by 123.48 points, or 0.34 per cent, at 36,159.77 in early deals.