In late afternoon trading, the benchmark was hovering around $40.16 a barrel.
This comes as WTI is set to hit its second-longest losing streak in more than 30 years, falling more than 3.8 per cent over the week.
WTI crude has plummeted more than 31 per cent over the past eight weeks, second only to a 10-week losing streak between December 1985 and March 1986, which resulted in the US benchmark dropping 54.33 per cent to $12.28 a barrel.
Over the last year the price of WTI crude has fallen 56.4 per cent. Oil prices are expected to stay low for a long period, figures by the US International Energy Agency suggested: earlier this month it forecast that the oil supply glut will last until the end of 2016.
Just over a week ago WTI crude crashed through its $42 floor to trade at a six year low.
Oil has been under increasing pressure in recent weeks amid worries of a global supply glut and a slowdown in the Chinese economy.
Brent crude was also trading 0.94 per cent down at $46.18 a barrel, after having fallen 3.64 per cent on Wednesday and 6.1 per cent over the week.