Crude oil prices eased on Tuesday, extending a recent move downward as a weak demand outlook amid poor US company results offset tight supply worries, traders said.
Brent North Sea crude for delivery in December fell 23 cents to $109.21 a barrel in London midday deals.
New York's main contract, light sweet crude for December, slipped 30 cents to $88.35 a barrel.
"Crude oil prices have been under pressure, tracking losses of the equity markets as fairly poor corporate earnings results weighed on market sentiment," said Sucden Financial analyst Jack Pollard.
Crude markets were weighed by worries over the US economy, with traders "bracing themselves for a continuation of last week's slew of weak earnings from the likes of Google, McDonald's and IBM," IG trading group said in a note to clients.
"There is still a bearish mood over the corporate earnings season with so many misses among blue-chip US stocks," it added.
Caterpillar, the world's biggest maker of construction and mining equipment, cut its sales outlook on Monday.
The company, considered a bellwether of the global economy, reduced its profit and sales forecast for full-year 2012, suggesting a sharp slowdown in the fourth quarter.
Oil prices had fallen on Monday in the wake of sharp pre-weekend losses, also as investors balanced poor Japanese export data against Middle East unrest.
Japan on Monday posted its worst September trade figures in more than 30 years.
The country has been struggling to turn around its fortunes following the March 2011 earthquake and tsunami disaster, while also suffering from Europe's debt crisis, slowing Chinese demand and the strong yen.
All eyes were also on violence in the oil-rich Middle East region, as hopes of a truce in war-torn Syria during this week's Muslim Eid al-Adha holiday remained slim on Tuesday as clashes showed no signs of easing and the death toll mounted.
Elsewhere, Anglo-Dutch oil group Shell on Tuesday said it may not meet contractual obligations on certain exports from Nigeria because of theft and damage to key pipelines in the country's oil region.