(Updates with markets closed)
BUENOS AIRES, Jan 24 (Reuters) - Argentine stocks closed sharply higher on Thursday, mirroring a rebound in global markets on revived investor optimism over U.S. government efforts to stimulate the world's biggest economy.
The MerVal index .MERV of 42 leading companies closed 3.97 percent higher at 1,966.46 points, rebounding from a 2.96 percent loss a day earlier when global markets were roiled by concerns the U.S. economy is headed for a recession.
On Thursday, U.S. lawmakers agreed on the outlines of an economic stimulus package, first announced last week, that would grant tax rebates. Expectations a rescue plan for U.S. bond insures will help avert further credit losses also helped push prices higher.
"The (news) from the United States helped the MerVal rebound with oil-related shares leading the way," said Dionisio Corneille, trader at a firm that bears his name.
"The Argentine market should have risen even higher since it was one of the most affected in recent weeks," he added.
This week, the Argentine stock market fluctuated strongly due to fears of a U.S. recession, accumulating a 1.8 percent loss during the last four sessions.
On the broad market, volume was $48.4 million, while 60 issues advanced, 13 retreated and five remained unchanged.
Buenos Aires-listed shares of Petrobras Brazil APBR.BA soared 10.2 percent to close at 162 pesos, while Tenaris (TENA.BA) (TS.N), the major producer of tubes for the oil industry, climbed 6.14 percent to 60.5 pesos.
Argentine bonds rose on the domestic maket, ending 1.1 percent higher on average, led by peso-denominated Discount bond ARDISCP=RASL, which climbed 2.7 percent in over-the-counter trade.
Bonds shed nearly 2.5 percent over the two previous sessions.
The peso strengthened slightly. In informal trade between foreign exchange houses, as measured by Reuters, the currency ARSB=firmed 0.08 percent ending at 3.1825/3.185 per dollar.
In formal interbank trade, the peso ARS=RASL also firmed 0.08 percent to close at 3.1525/3.155. (Reporting by Jorge Otaola; Writing by Gaspard Sebag;)