World oil prices fell on Thursday as traders eyed a possible delay to US-led military action against Syria, one day after New York crude hit a two-year high point.
New York's main contract, West Texas Intermediate (WTI) for delivery in October, sank $1.06 to $109.04 per barrel.
Brent North Sea crude oil for October dropped 91 cents to $115.70.
The oil market had surged in intra-day trading on Wednesday in anticipation of a western crackdown on Syria.
At one stage, New York crude hit $112.24 to reach the highest level since early May 2011, while Brent soared to $117.34, last seen in late February.
"Oil prices have slipped this morning, after surging yesterday on concern that the Syrian conflict could spread throughout the Middle East and threaten oil supplies," said trader Matt Osborne at British-based energy broker Inenco.
"The possibility of a delay in a US-led military strike on Syria has helped to clam concerns over disruptions to Middle East supply.
"WTI oil has dropped from a two-year high also helped by higher-than-expected US crude stockpiles, which rose the most in four months."
UN chief Ban Ki-moon said on Thursday his investigating team would report by the end of the week on suspected chemical weapons attacks in Syria as the US and its allies held back from immediate punitive military action against Damascus.
US President Barack Obama said he had yet to sign off on a plan to strike Damascus over the attacks which activists say killed hundreds of people and threatened to draw the West into the 29-month conflict in Syria.
A Western air bombardment had appeared imminent earlier this week, but US allies were increasingly reluctant to act before hearing the results of a UN probe into the alleged poisonous gas attacks last Wednesday.
"Concerns over an immediate Western military action in Syria has eased somewhat after the UK government, one of America's closest allies, said it will wait for the results of a UN investigation into the suspected chemical weapons attack before deciding if it will take action," noted GFT analyst Fawad Razaqzada.
Although Syria is not a major oil producer, traders are nervous about a broader conflict in the crude-rich Middle East region.
Key Damascus allies Russia and Iran have warned against any Western intervention in the civil war, saying it could set off a wider regional conflict.
"The (oil) market remains nervous over an imminent US and UK led strike against Bashar al-Assad's forces in retaliation for recent chemical attacks against innocent citizens," said VTB Capital analyst Andrey Kryuchenkov.
"However, the likes of Russia are urging restraint, with the UN weapons inspectors yet to deliver their final verdict.
"Britain was already seeking a UN Security Council resolution against Syria, but we still believe it will not be essential for the anti-Assad allies, who are determined to pursue a military response at this point."
Some commentators have warned that any US attack would mean that Washington was in effect fighting on the side of Al-Qaeda, whose fighters have joined rebels in the battle to oust Assad.
Kryuchenkov predicted that any eventual military action against Syria would not last a long time.
"We believe that any strike would be a short-term air attack against military installations inside Syria, with precise missile hits, and that the operation is unlikely to last for more than a week," he added.
"The Western-led coalition would seek to avoid any ground involvement or a protracted involvement into the raging civil war like it happened in Libya."