Oil prices dropped by more than three per cent today as they head for their biggest weekly fall since January, with investors worrying over US crude stockpiles.
Brent crude futures ended the session at $45.45 per barrel, down $1.44 or 3.07 per cent.
U.S. crude's West Texas Intermediate (WTI) futures closed down $1.54 or 3.45 per cent at $43.16 a barrel.
The fall comes after a surprise rise in US stockpiles pushed prices down yesterday, and the total nine per cent decline for both Brent and WTI for the week so far marks the biggest decline in prices since mid-January.
Earlier this week the American Petroleum Institute showed US crude stocks rose by 942,000 barrels to 525.5m barrels in the week to 26 August.
The figures had represented more than double what the markets had expected.
A Reuters poll of 34 analysts and economists forecast Brent would average $45.44 a barrel in 2016, slightly lower than last month's forecast of $45.51.
The reductions came after a month of improvement in prices, which climbed more than 20 per cent from the beginning of August over hopes of a possible output freeze from members of the Organisation of Petroleum Exporting Countries.