Mumbai, April 25 -- The Indian rupee is seen extending upside against the dollar in opening trades on Friday despite a rebound in dollar overseas. Broadly positive cues from Wall Street overnight, amid optimism about a possible favorable outcome from the ongoing tariff negotiations between the U.S. and several partner countries, particularly China is supporting the local unit. Yesterday, rupee regained momentum and ended higher by 16 paise to 85.29 against the US dollar. Indian shares however ended slightly lower on Thursday. The benchmark S&P/BSE Sensex fell 315.06 points, or 0.39 percent, to 79,801.43. The broader NSE Nifty index ended down 82.25 points, or 0.34 percent, at 24,246.70 amid the monthly F&O expiry for April series contracts....