Brent North Sea crude for delivery in January fell 39 cents to $83.57 a barrel in London trade.
New York's main contract, light sweet crude for December, shed 43 cents to $81.31.
Stock markets sank in Asia and Europe on Tuesday, as investors dumped risky assets on the back of fading enthusiasm over Ireland's bailout and a spike in tensions between North and South Korea.
"It seems that the oil market is out of breath, struggling again for some direction," said Sucden analyst Myrto Sokou.
"Renewed concerns about a wider eurozone crisis continue to dominate the market, causing tentative and nervous trading conditions.
"It is likely that the euro will receive further pressure as the initial relief about Ireland’s bailout plan has been overshadowed by ongoing concerns about a wider debt crisis in the eurozone."
The European single currency meanwhile slid to $1.3592 from $1.3622 in New York late on Monday, as the greenback was boosted by its safe-haven status in times of economic and geopolitical uncertainty.
A stronger greenback boosts dollar-priced crude oil, which becomes more expensive for buyers using weaker currencies.
What the stars mean:
★ Poor ★ ★ Promising ★★★ Good ★★★★ Very good ★★★★★ Exceptional