Amin Nasser, chief executive officer of Saudi Arabian Oil Co. (Aramco), speaks at an energy market conference in Houston, Texas last week. A planned stock market flotation of Aramco now looks likely to be delayed until 2019 at least.  Photograph:  Carter Smith/Bloomberg

Investors waiting for the chance to buy a piece of Aramco, Saudi Arabia’s state-owned oil behemoth, will probably have to wait. Saudi officials are re(...)