SK On, South Korean energy group SK Innovation Co Ltd's battery unit, has been in talks with private equity firms including Carlyle Group Inc and BlackRock Inc among others, according to Maeil Business Newspaper, citing the investment banking industry.

The newspaper added Carlyle Group and SK On had been negotiating detailed terms.

SK On declined to comment on ongoing talks with potential investors. Carlyle Group and BlackRock were not immediately available for comment.

In March, SK Innovation CEO Kim Jun said he expected a pre-IPO deal for SK On would be concluded by around the first half of this year, adding the IPO would not likely take place until after 2025.

Kim said he could not disclose the amount of pre-IPO funding SK On was seeking, but the figure was not much different from that reported by media outlets, which ranged between 3 trillion won and 4 trillion won.

While SK Innovation had been aiming for its loss-making battery unit to break even by the fourth quarter of this year, the company said in April that SK On's turnaround could take longer than previous guidance due to surging raw material prices and a prolonged global chip shortage.

Spun out of SK Innovation last year, SK On, whose clients include Ford Motor Co, Hyundai Motor Co and Volkswagen AG among others, has production sites in the United States, South Korea, China, Hungary and Turkey.

($1 = 1,308.1700 won)

(Reporting by Heekyong Yang and Joyce Lee; Editing by Mark Potter)