The US oil price fell below the symbolic threshold of $50 a barrel for the first time since April 2009, before finishing the day at $50.05. The price of Brent crude also fell on Monday, dipping 6% to $53 a barrel.
The currency closed at R$ 2.76 per US$ 1 dollar. Domestic politics, international oil prices, US Fed measures and Russian ruble drop to blame.
Brent and US crude oil plunged as much as 6.50 dollars a barrel on Thursday, the steepest one-day falls since 2011 following on OPEC's decision against cutting output despite a huge oversupply in world markets.
The global oil market slump looks likely to continue, with prices possibly nearing 70 dollars a barrel in the short term, an official of Russian gas producer Gazprom said. Crude fell more than on dollar a barrel on Thursday to a four-year low below 83 a barrel as growing concerns over the global economy stretched a four-month rout.
Global oil prices have fallen further after the International Energy Agency (IEA) reported higher output and cut its forecast for demand growth. Brent crude fell 2.72 to 86.17 dollars a barrel before seeing a slight recovery, while US crude dropped 1.75 to 83.99.
Price cuts by key exporter Saudi Arabia helped send global crude prices to their lowest point in more than two years Thursday before they recovered in late trade.