Talks between SK Group and Doosan Group over the sale of a controlling stake in SK Siltron are expected to conclude this week, seven months after Doosan Corp. was selected as the preferred bidder. According to industry officials on Tuesday, SK Inc. is considering putting the sale of its 70.6 percent stake in silicon wafer maker SK Siltron on the agenda for its board meeting on Friday. As part of its portfolio reorganization, SK Group selected Doosan Corp. as the preferred bidder for the stake in December last year. The two sides were initially anticipated to reach a sale and purchase agreement within the first half of this year, but both repeatedly said in regulatory filings that a definitive agreement had not yet been finalized. At the time, SK Siltron was valued at around 5 trillion won ($3.4 billion). This year, however, the value of silicon wafers has increased as a result of the semiconductor upcycle, with the company's valuation now estimated at around 7 trillion won, prompting SK to put the agreement on hold. SK Siltron is the world's third-largest silicon wafer maker by revenue,