Listen to this article
The US benchmark price for oil fell below $44 a barrel for the first time since November 15 amid a resurgence in the US shale industry and as Opec struggles to curb supplies.
West Texas Intermediate fell as much as 3.9 per cent to $43.76 a barrel during morning Asia trading after tumbling 4.8 per cent on Thursday.
Oil prices began surging in late November and early December just before Opec approved its first cut in eight years.
Brent Crude, the international benchmark, traded below $47 a barrel for the first time since November 30.
Get alerts on Oil when a new story is published