US shale producers are turning up the heat on OPEC again — but this time the cartel’s adversaries aren’t a bunch of debt-fueled wildcatters. They’re the world’s biggest and deepest-pocketed oil companies.

Saudi Arabia and allied oil producing countries said on Sunday they would postpone a plan to gradually increase oil output until the end of the year, extending their output cuts by one month.

Oil prices opened $1 dollar higher following the weekend to trade at 73.80 a barrel when markets opened. Click to read.