SK Siltron's headquarters in Gumi, North Gyeongsang Province / Courtesy of SK Siltron

SK Inc., SK Group's holding company, said Friday it has signed a 2.3 trillion-won ($1.6 billion) stock sale deal to hand over its stake in chip materials affiliate SK Siltron to Doosan Group.

Under the decision made at a board meeting held earlier in the day, SK will sell its 70.6 percent stake in the affiliate to Doosan, a South Korean engineering and energy conglomerate, according to a regulatory filing.

The move comes about seven months after SK named Doosan as the preferred bidder in December to acquire SK Siltron following an evaluation on corporate growth potential, job stability and other acquisition conditions.

Established in 1983, SK Siltron is the country'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.