Shares in SK Energy rose up to 4.7 percent on Friday after the oil refiner said it may not list a unit, opting instead for an internal merger that would give it full control of the valuable affiliate.
Analysts said the refiner's decision to potentially shelve an initial public offering for SK Incheon, which had been expected to fetch some $700 million to $1 billion, could mean profits from the unit would flow to current shareholders of SK Energy.
SK Energy owns more than 90 percent of SK Incheon, which Samsung Securities valued at 3.5 trillion won ($3.73 billion) in a recent research note.
SK Energy shares were 3 percent in early trade to 155,000 won, after earlier gaining as much as 4.7 percent, while affiliate SK Holdings added 1.5 percent to 165,000 won.