By Kwanwoo Jun

SK Innovation Co. swung to a net loss in the second quarter due to weaker refining margins and lower oil prices amid sluggish demand caused by the Covid-19 pandemic.

Net loss for the quarter ended June 30 was 345.83 billion Korean won ($288.2 million) compared with net profit of KRW155.44 billion in the same quarter a year earlier, the South Korean oil refiner said Wednesday. That missed a FactSet consensus forecast for a net loss of KRW153.58 billion.

Revenue during the quarter fell 45% to KRW7.200 trillion, as the company swung to an operating loss of KRW439.74 billion from an operating profit of KRW493.67 billion.

SK Innovation expects its refining margins to improve on growing oil demand in the second half of the year thanks to stimulus and the possible recovery in the global economy.

Write to Kwanwoo Jun at kwanwoo.jun@wsj.com