Commodities came under pressure after the World Bank cut its forecasts for global growth, reinforcing worries of a gloomy economic outlook.
Alcoa boosted investor optimism by posting its best annual results since 2008.
Cash-strapped Venezuela is looking to Beijing, its top financier, for assistance amid falling oil prices and mounting fears of default.
“Saudi Arabia can take a step to have a productive role in this situation,” a top Iranian official said.
Global benchmark Brent crude has fallen 49 percent in 2014.
Brent crude oil fell to a 5-1/2-year low on Tuesday as a global supply glut outweighed concerns of lost supply from Libya.
Oil prices rose on Monday, after dropping for the past two sessions, as escalating clashes stoked worries about supply from the OPEC member.
Oil prices could begin finding a new equilibrium by the end of 2015, even in the absence of any production cuts by OPEC.
Saudi Oil Minister Ali al-Naimi blamed falling oil prices on speculators and lack of cooperation from non-OPEC members
As oil prices go down, tensions are on the rise in Nigeria.
"The fundamentals should not lead to this dramatic reduction [in price]," OPEC Secretary General Abdullah al-Badri says Sunday.
Brent is down roughly 9 percent this week, some 45 percent below its June peak above $115 per barrel.
The benchmark for U.S. crude oil prices tumbled below $60 a barrel Thursday, a psychologically important level.
The Dow tumbled after OPEC slashed its forecast for 2015 production by 300,000 barrels per day to 28.9 million barrels.
“Iran and people of the region will not forget such conspiracies," the Iranian leader said on Wednesday.
The Dow and S&P 500 dropped Monday as the energy sector tumbled after Morgan Stanley slashed its forecast for Brent crude.
Lower crude oil prices are good for U.S. consumers and bad for oil services firms as well as some oil-producing nations.
Warnings over further economic turmoil in Venezuela are becoming louder after OPEC declined to cut oil production last week.
Prices at the pump are expected to remain low as OPEC maintains its current level of production.
A price war would hurt top non-OPEC exporter Russia, which has clashed with Saudi Arabia over Moscow's support for Syrian President Bashar Assad.
Some fund analysts have said that oil prices could slide to $60 per barrel if OPEC does not agree to a significant output cut.
OPEC may be forced to pull back on production to keep oil prices from sinking lower.