Oil fell below $45 in New York yesterday as an Organization of the Petroleum Exporting Countries (Opec) deal to curb output appeared in jeopardy after Iran and Saudi Arabia failed to bridge differences.

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.