Oil prices are down by more than one per cent today as investors fear increased production in the US will overshadow the Organisation of the Petroleum Exporting Countries' (Opec) efforts to reduce the global supply glut.
Brent crude futures were down from a 2014 high by 1.07 per cent at $68.57 a barrel while West Texas Intermediate (WTI), the US benchmark, fell 1.22 per cent to $63.17 a barrel.
Today's falls could lead to the biggest weekly price decline since October, according to Reuters.
Mike van Dulken and Henry Croft, analysts at Accendo Markets, said the concerns of weak demand and rising supply were putting a dent in recent bullishness.
In its monthly oil report yesterday, Opec forecast increased oil supply from countries outside the cartel while global demand is set to slow.
"As a result, global benchmark Brent fell to a 10-day low of $68.50 overnight before finding support, while US crude briefly dipped below $63 before recovering to $63.10," the analysts said.
As of 12 January, US crude oil production was 9.75m barrels per day (bpd), up from 9.49m at the start of the year, according to data from the Energy Information Administration (EIA).
US production is expected to break the 10m bpd soon.