Moreover, the US dollar's gain against some currencies overseas put the rupee on the backfoot, forex dealers said.
However, a higher opening of the domestic equity market capped the rupee's losses.
The rupee had lost 5 paise to end at 66.81 per dollar yesterday on fresh demand from banks and importers for the US currency despite firm domestic equity markets.
Meanwhile, the benchmark BSE Sensex rose further by 88.86 points or 0.31 per cent to 28,212.30 in early trade.