The rupee depreciated 6 paise to 77.50 against the US dollar in the opening trade on Wednesday as a surging American currency in the overseas markets and persistent foreign fund outflows weighed on investor sentiment. Besides, rising global crude prices impacted the domestic unit, forex traders said. However, a higher opening in the domestic equity market restricted the rupee's fall, they added.

At the interbank foreign exchange, the rupee opened weak at 77.57 against the American dollar, then gained some lost ground to quote at 77.50, registering a fall of 6 paise over the last close. It was moving in a tight range of 77.57 to 77.48 in early deals. In the previous session, the rupee had settled at 77.44 against the American currency. The dollar index, which gauges the greenback's strength against a basket of six currencies, was trading 0.11 per cent higher at 103.47.