Oil could slump to $20 a barrel

Oil deepened its weekly decline as Goldman Sachs Group said a global supply surplus could force prices to $20 a barrel. Futures fell after two weeks of gains. Goldman said yesterday the world’s oil glut is even bigger than it thought.

Oil has fluctuated since slumping below $40 a barrel three weeks ago as concern over slowing growth in China fuelled volatility in global markets.

A US Senate vote paved the way for president Barack Obama to ease financial penalties for doing business with Iran, which would allow an increase in the nation’s oil exports. US stockpiles continue to rise, even as production slows.