The activist investor plans to push the oil refiner to consider selling or spinning off its energy-transportation business.

Phillips 66 shares are jumping 4% in intraday trading Tuesday following a report by The Wall Street Journal that Elliott Investment Management has built a more than $2.5 billion stake in the oil refiner.

Elliott Investment Management confirms a more than $2.5B stake in Phillips 66 and will seek to streamline the company, most notably with the sale or spinoff of its midstream business.