Vitol’s South Africa Gas-Station Deal Flags Refining Concern (1)

Vitol Group’s acquisition of a majority stake in South Africa’s largest fuel-station chain puts pressure on already shrinking domestic refining capacity due to the trading house’s ability to source and store imports, according to an antitrust investigator.

A Vitol unit in February agreed to buy Petroliam Nasional Bhd.’s 74% stake in Engen Ltd., helping the energy trader form a group with 3,900 service stations across 27 African nations. That deal came as a South African refining system — plagued by underinvestment — lost about half of its oil-processing capacity in recent years.

The local fuel manufacturing ...