(Adds bonds and peso, quote and details)
BUENOS AIRES, Jan 2 (Reuters) - Argentine stocks surged on Friday in the first session of the new year on strong gains in energy-related stocks and buoyed by other global markets.
The benchmark MerVal index .MERV ended 5.89 percent higher at 1,143.33 points, after closing 2008 with a loss of almost 50 percent.
"The MerVal has bounced back in a session with significant global gains, driven by stocks related to oil and the energy sector," said Ruben Pascuali, a trader at the Mayoral Bursatil brokerage.
A rise in crude prices helped Brazilian state oil company Petrobras APBR.BA gain 10.48 percent to 45.3 pesos per share. Index heavyweight Tenaris (TENA.BA), the world's biggest producer of seamless steel tubes for the energy industry, jumped 7.73 percent to 39 pesos per share.
However, trade volume on the broad market remained thin at $9.5 million. Of active shares, 42 advanced, three retreated and 11 were unchanged.
Meanwhile, locally traded Argentine bonds gained 0.6 percent on average in light over-the-counter trade, with the dollar-denominated Discount 2033 ARDISCD=RASL rising 2.1 percent to an ask price of 34.00.
On the foreign exchange market, the peso was almost flat in a lackluster session following the holiday.
In informal trade between foreign exchange houses ARSB= as measured by Reuters, the peso firmed just 0.07 percent at 3.5325/3.5375 to the dollar.
In formal interbank trade ARS=RASL, where the central bank regularly intervenes, the local currency weakened 0.22 percent to 3.4575/3.46 per U.S. dollar. (Reporting by Walter Bianchi; Writing by Helen Popper; Editing by Leslie Adler)