The company posted an operating loss of 683 billion won ($543.28 million) for October-December, compared with a loss of 62 billion won a year earlier.

Revenue rose 40% to 19 trillion won, slightly missing an average analyst estimate of 20 trillion won, according to Refinitiv SmartEstimate.

SK Innovation, which has a total refining capacity of 1.115 million barrels per day (bpd) at its plants in Ulsan and Incheon, said it operated its facilities at 71% of capacity on average in the quarter, down from 85% in the third quarter.

Peer S-Oil Corp, whose main shareholder is Saudi Aramco, said last week that Asia's regional refining margins were expected to remain elevated in 2023 over pre-2022 levels amid ongoing refinery shortages, despite demand growth woes.

Shares of SK Innovation, which also has a business supplying batteries for electric vehicles (EV), were trading down 0.1% in morning trade, versus a 0.2% rise in the broader KOSPI.

($1 = 1,257.1700 won)

(Reporting by Heekyong Yang and Joyce Lee; Editing by Christopher Cushing and Kim Coghill)

By Heekyong Yang and Joyce Lee