South Korea's antitrust regulator launched deliberations on Wednesday against two domestic oil refiners, following an investigator report accusing the companies of illegally exchanging information and manipulating prices.

The Korea Fair Trade Commission (KFTC) said the investigation report recommended fines and corrective orders for SK Energy and HD Hyundai Oilbank over allegations that the two firms exchanged information and reached collusive agreements on gasoline, diesel, and kerosene prices.

According to the report, the two companies continuously exchanged information about sales strategies from February 2022, just before the outbreak of the Russia-Ukraine conflict, until shortly after the outbreak of a US-Iran war in March 2026.

Investigators alleged that the two firms engaged in price manipulation practices since the Middle East crisis. The total sales involved amounted to approximately 44.1 trillion won (about US$33.2 billion), with an average daily scale of roughly 30 billion won.

The report stated that the companies set prices while sharing information with each other, conduct that improperly restricted market competition and violated the Monopoly Regulation and Fair Trade Act.

The head of the KFTC's cartel investigation bureau said, "We determined that the two companies began sharing information against the backdrop of drastic energy price fluctuations triggered by the war." He also noted that the two firms together hold nearly half of the market share and are capable of influencing the competitive landscape.

The regulator said it will give the companies an opportunity to present their side before making a final ruling, and the firms have eight weeks to submit written responses. The investigation report is not binding on the KFTC's final decision.

In 2025, SK Energy and HD Hyundai Oilbank held 28.1% and 21% respectively of South Korea's gasoline, diesel, and kerosene production and sales market. KFTC data shows that South Korea's four refiners — the other two being GS Caltex and S-Oil — together account for 98% of the market.

SK Energy said it is carefully reviewing the investigation report and will fully present its position based on facts during the KFTC's deliberations. An official from HD Hyundai Oilbank said the company will fully elaborate its views on the relevant legal disputes. The official said, "All the information exchanged between the two parties was either publicly available or obtainable through various channels, and it did not affect the company's pricing and sales strategies."