BUENOS AIRES, Sept 25 (Reuters) - Argentine stocks jumped more than 3 percent on Thursday, buoyed by investor optimism the U.S. Congress was nearing a bailout plan for the country's financial sector.
The MerVal index of leading shares .MERV closed at 1,707.98 points after rising nearly 3.7 percent earlier in the session.
"All eyes are on the United States and whether lawmakers will approve the rescue plan," said Juan Diedrich, a trader of Capital markets Argentina.
Buying led by institutional investors helped drive up locally-traded shares in Brazil's state-run oil company Petrobras APBR.BA(PETR4.SA) which rose 6.32 percent to 59.45 pesos.
Telecom Argentina (TEC2.BA), one of Argentina's top telephone companies, also climbed, rising 6.38 percent to 8.51 pesos.
Trade volume on the overall market was a moderate $30 million. Of active shares, 83 rose, 29 fell and 18 were unchanged.
On the debt market, investors pocketed profits from recent gains as locally traded government bonds shed 0.4 percent on average in over-the-counter trade, led by a 2.6 percent fall in the peso-denominated Par bond ARPARP=RASL.
The peso currency, which is heavily controlled by the Central Bank, weakened 0.16 percent to 3.11/3.1125 per dollar ARS=RASL in formal interbank trade. In informal trade between foreign exchange houses, as measured by Reuters, the peso gained 0.16 percent to 3.155/3.1575 per dollar ARSB=.
The peso has shed 2.78 percent so far this month in informal trade. (Reporting by Jorge Otaola; Writing by Kevin Gray; Editing by Diane Craft)