S-Oil Corp. said Thursday its second-quarter net profit more than doubled from a year earlier on the back of widened refining margins helped by higher oil prices.

Net profit came to 1.01 trillion won ($775.2 million) in the April-June period, up 146.9 percent from 410.7 billion won a year earlier, the Seoul-based subsidiary of Saudi Arabia's Aramco said in a regulatory filing.

Operating profit reached 1.72 trillion won, more than tripling from the previous year's 571 billion won. Sales increased 70.5 percent on-year to 11.44 trillion won over the cited period.

The earnings fell below market expectations. The average estimate of net profit by analysts stood at 1.13 trillion won, according to the survey by Yonhap Infomax, the financial data firm of Yonhap News Agency.

"Refining margins widened as the rise in international oil prices pushed up the unit prices. The petrochemical sector made a turnaround and lubricant oil profits also improved," the company said in a release.

Refining margins, a key gauge of refiners' profitability, are linked to international oil prices. Higher crude prices usually mean greater margins, or the difference between the total value of petroleum products and the cost of crude and related services.

A recovery in demand from eased COVID-19 border restrictions, and a tight supply amid the Russia-Ukraine war, have also helped boost the refining margins and inventory gains, it added.

Refinery sales reached 9.25 trillion won for the second quarter, with the operating profit coming in at 1.4 trillion won.

The petrochemical division posted 1.3 trillion won in sales and 18 billion won in operating profit. Sales from the lubricant oil sector came to 888 billion won and the operating profit reached 258.9 billion won. (Yonhap)