Rising for the third day, the rupee firmed up by 18 paise to 68.45 against the US dollar in opening trade today on continued selling of the American currency by exporters and banks amid foreign capital inflows. Forex dealers said besides sustained selling of the greenback, a higher opening of the domestic equity markets boosted the local unit at the interbank forex market.

BSE Sensex rose 162.56 points

However, the dollar's strength against some currencies overseas capped the gains. Yesterday, the rupee had gained by 5 paise to end at 68.63 against the US currency.  The benchmark BSE Sensex rose 162.56 points, or 0.42 per cent, to hit an all-time high of 38,050.12. The NSE Nifty too scaled a new peak of 11,495.20 in early trade today.