Elliott Investment Management is seeking seats on the board of oil refiner Phillips 66, the latest effort in a multi-year campaign pushing the company to sell assets, improve operational performance and bolster board oversight.

Activist Elliott Management has become BP’s third-largest shareholder after building a near-5 per cent stake worth almost £3.8bn, as it seeks to force the troubled UK oil major to cut spending on renewable energy and make big divestments, according to two people close to the situation.

With a more-than-$2.5 billion stake in Phillips 66, Elliott has pushed for a streamlining of the oil refiner and seeks more representation on the company’s board.

Phillips 66 (NYSE:PSX) +1.6% in early trading Wednesday as activist investor Elliott Management, which has built a $2.5B-plus stake in the refiner, discloses it will seek seats on the company's board.