Currency: Rupee strengthens 21 paise to close at Rs 81.58 against US dollar

In the forex market, the rupee today strengthened 21 paise against the US currency. The domestic unit closed at 81 rupees and 58 paise against the dollar. The dollar index, which indicates the US dollar's strength against a basket of six other leading currencies, rose 0.11 percent to trade at 103.35 in intra-day trade.