Oil hovered around $70 a barrel today, steadying after a sharp two-day sell-off following an unexpected rise in US petrol stocks.
New York's main contract, light sweet crude for delivery in June, added 18 cents to 70.12 dollars per barrel in electronic deals before the market's official opening on Friday.
The contract had plummeted by nearly $5 or 6.3% in value over the course of Wednesday and Thursday.
The price of London's Brent North Sea crude for June delivery gained 50 cents to $70.79 per barrel on Friday, after losing 5.8% of its value over the last two days.
US petrol reserves rose 2.1m barrels to 202m in the week to April 28, according to the DoE. However, markets had bet on a fall of 650,000 barrels.
US crude oil reserves rose 1.7m barrels to 346.7m barrels. Analysts had expected a fall of 150,000 barrels.
However, the market remained on edge over the risk of disruption from fourth-largest oil exporter Iran, locked in a dispute with the West over its nuclear ambitions, which is likely to keep upward pressure on prices. Also unrest in Nigeria and new developments in Bolivia are causes for market concern.
At the United Nations, Western powers plus China and Russia held a first round of talks on a draft resolution that demands Tehran suspend nuclear activities. The sponsors have warned they will push for sanctions if Tehran persists.
In Nigeria, a quarter of oil production remained shut down due to militant violence, although a major oil union yesterday suspended a planned shutdown of the local unit of Exxon Mobil after agreeing to a deal.
Oil markets have also been rattled this week by news that Bolivia has decided to nationalise its energy sector.
Bolivian President Evo Morales issued a decree on Monday to nationalise the South American country's oil and natural gas industries.
