The rupee sustained its upward momentum for the third straight session and gained 6 paise to 82.91 against the US dollar in early trade on Wednesday, tracking a weak American currency and positive equity market sentiment. However, selling pressure from foreign equity investors amid elevated level of crude oil prices resisted a sharp gain in the domestic currency, analysts said. At the interbank foreign exchange, the domestic currency opened at 82.90 and slipped to 82.91 against the greenback in initial deals, registering a gain of 6 paise from its previous close. The rupee settled 4 paise higher at 82.97 against the US dollar on Tuesday, a day after gaining 4 paise in the preceding trading session on Friday. The currency market was closed on Monday on account of Chatrapati Shivaji Maharaj Jayanti. Meanwhile, the dollar index, which gauges the greenback's strength against a basket of six currencies, was 0.07 per cent lower at 103.90. Brent crude futures, the global oil benchmark, .