Argentine stocks fell 6.07 percent in afternoon trading Monday, hit by ongoing oil market turmoil that saw US crude prices dip below $50 a barrel for the first time since 2009.
Although a natural gas producer with good oil prospects, Argentina is a net oil importer and some businesses may benefit from cheap fuel, but oil firms are already a major factor in the Buenos Aires stock exchange.
Local shares in Brazilian state oil giant Petrobras led the losses, shedding 9.26 percent.
Electricity distributor Transener lost 7.25 percent, while shares in Italian steelmaker Tenaris fell 7.65 percent.
The Argentine peso shed 0.23 percent to 8.57 to the dollar.
Argentina's Merval stock index has been battered in recent weeks by sliding oil prices and domestic economic worries including spiraling inflation, an economic slowdown and a debt default.
Markets also sank Monday in Europe and the United States, weighed down by concerns about the eurozone and punishing losses for petroleum-related stocks.