Seoul: SK Group is considering selling a controlling stake in its semiconductor wafer subsidiary SK Siltron Co. as part of a restructuring plan of the group's key businesses, according to industry sources Tuesday.

According to Yonhap News Agency, SK Inc., the group's holding company, has been in contact with various private equity funds to explore the potential sale of a controlling share of the subsidiary, which SK purchased from LG Group in 2017.

The amount of share under consideration is reportedly at 70.6 percent, including the 51 percent share owned by SK Inc. and a 19.6 percent share tied to a total return swap (TRS) contract.

SK Siltron is South Korea's sole dedicated producer of semiconductor wafers, a key material used in chip manufacturing. The company ranks third globally in terms of market share for 12-inch wafers.

Market analysts estimate SK Siltron's valuation at around 5 trillion won (US$3.38 billion).

"Various options are being reviewed as part of our rebalancing efforts, but nothing has been finalized," an SK official said.

SK Group has been undertaking aggressive restructuring since last year to optimize its business portfolio, focusing on financial soundness and long-term strategic growth.