Brent crude declined below $104 a barrel on Thursday amid ample supplies despite the current situation in Ukraine and Iraq, and concerns over weak demand.
September Brent crude fell 48 cents to $103.80 a barrel while US crude was down 46 cents at $97.13 a barrel, Reuters reported.
The Ras Lanuf port in Libya has restarted oil exports following a year of blockades by armed protesters, while US crude stocks increased unexpectedly last week.
The continuing violence in Iraq has had little impact on supply from the country’s southern oil fields.
Citing a European diplomat, Reuters reported that the European Union is looking at ways to tighten sanctions to stop Islamic State militants from selling oil from fields they have overrun in Syria.
Data from the Energy Information Administration (EIA) has revealed that US crude inventories increased by 1.4 million barrels last week.
The EIA has increased its estimate of the US crude production forecast for 2014 to 8.5 million barrels per day (bpd), compared with an earlier estimate of 8.42 million bpd.
Output in 2015 is estimated to be 9.3 million bpd, which would represent the highest annual average level of production since 1972.
Data showed that the German economy shrank in the second quarter and France posted no growth, while Chinese data that demonstrated a 6% decline in its July implied oil demand from June also added to concerns about weak demand.
