Oil prices slumped below $40 a barrel on persistent concerns over a global supply glut, heaping more pressure on OPEC to cut output at its upcoming meeting in the Austrian capital.
The US benchmark West Texas Intermediate for delivery in January tumbled $1.91 to close at $39.94 a barrel — the first time it has ended under $40 since late August.
In London, Brent North Sea crude for January declined $1.95 to $42.49 a barrel.
World oil prices have fallen by more than 60 percent in value since June last year on high supplies, weak demand growth and a strong dollar.
