Global oil prices traded mixed on Tuesday as dealers weighed up supply factors in the Middle East and United States, analysts said.
New York's main contract, West Texas Intermediate (WTI) for delivery in December, slid 81 cents to $94.33 a barrel.
Brent North Sea crude for December edged up four cents to $106.44 a barrel.
"Brent is ... defending the gains it made over the past two days of trading. It is continuing to find support from the risks to supply," said Commerzbank analyst Carsten Fritsch.
"After the nuclear talks with Iran were adjourned without any result having been achieved at the weekend, it is clear that hopes harboured by market participants that Iran?s oil supply would soon return to the market were premature.
"What is more, the situation in Libya is continuing to give little reason for optimism that the country?s oil production might normalise in the foreseeable future," he added.
Marathon talks at the weekend in Geneva between Iran and major powers failed to produce a long-elusive deal which could ease crude export sanctions on Tehran and bring the major oil producer back into the global market.
But negotiators have insisted they are drawing closer to securing a short-term deal that would freeze Iran's nuclear activities while both sides work on a comprehensive agreement.
Iran has been crippled by the sanctions aimed at bringing an end to its nuclear drive, which the West claims is being used to develop atomic weapons. Iran denies the assertion.
The so-called P5+1 group of major powers -- Britain, France, the United States, Russia and China plus Germany -- and Iran will reconvene again in Geneva on November 20 to try to iron out the short-term deal.
In Vienna, the Organization of Petroleum Exporting Countries raised its estimate for global demand for oil this year and next, counting on economic recovery in advanced countries.
In its monthly report, it raised its estimate for demand this year by 400,000 barrels per day to 89.78 mbd -- and held it at 90.78 mbd for 2014.
New York oil prices were meanwhile under pressure on expectations of a fresh surge in US crude stockpiles, traders said.
Official data released last week showed US crude inventories rose for the seventh straight week, indicating soft demand in the world's biggest economy.
The US Department of Energy's official crude stockpiles report for the week to November 8 will be released on Wednesday.
The International Monetary Fund said on Tuesday that the Libyan economy was expected to contract by 5.1 percent this year owing to oil output disruptions triggered by protest blockades.
Protesters, including ex-rebels, demanding a fairer distribution of resources and jobs, have been blocking oil fields and export terminals, causing around $13 billion in losses to Libya's oil-dependent economy, authorities say.
Current output is estimated to have dropped to 250,000 barrels per day, from 1.5 million bpd before the protests erupted in July, an official at Libya's National Oil Company told AFP last week.