Elliott Investment Management has reportedly acquired a stake exceeding $2.5bn in Phillips 66 and plans to advocate for operational changes, including the sale of the company's midstream business. The news has seen Phillips 66 shares rise by 3.

Activist Elliott Investment Management on Tuesday disclosed a stake in Phillips 66 valued at more than $2.5 billion and said it is pushing the oil refiner to consider operational changes to boost its stagnant stock.

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.