SK Hynix posted an operating profit of 237 million euros (346 billion won) for the October-December period, compared with a loss of 1.3 billion euros (1.9 trillion won) in the same period a year earlier, with strong sales of its flagship products DDR5 and HBM3.

The company said those sales increased more than four and five times each last year due to solid demand for chips used in mobile applications and AI.

SK Hynix said its sales increased 47 per cent to 7.8 billion euros (11.3 trillion won) in the fourth quarter year.

However, it still recorded a full-year loss of 6.2 billion euros (9.1 trillion won) because of the year-long downturn.

SK Hynix last recorded a quarterly profit in the third quarter of 2022, after which an industry-wide downturn battered it.

"We achieved a remarkable turnaround, marking the first operating profit in the fourth quarter following a protracted downturn, thanks to our technological leadership in the AI memory space," SK Hynix vice president Kim Woo-hyun said in a news release.

Kim said the chip maker will "grow into a total AI memory provider" in 2024, equipped with "customised solutions" as it enters what it called "an era for a new leap forward. "

SK Hynix is South Korea's second-most valuable company, with a market capitalisation of more than 69 billion euros (101 trillion won), trailing Samsung Electronics' 303 billion euros (443 trillion won).

Samsung Electronics is scheduled to release its earnings on January 31.