Phillips 66 said on Wednesday it "plans to continue a constructive dialogue" with Elliott Investment Management after the company asked the U.S. refiner to revamp its board to boost lagging performance.

The activist investment firm has taken a $1 billion stake in Phillips 66, flagging that the company's stock, recently trading at about $118 per share, could hit $200 with improvements. It said management had laid out sensible performance targets but could use help achieving its full potential.

"We agree with Elliott that successful execution of our strategic priorities will drive substantial stock price performance and believe that we have the right management team and Board in place to deliver long-term, sustainable value," the refiner said in a statement after the markets closed.

As of market close, shares of Phillips 66 were up nearly 3.6%.

(Reporting by Seher Dareen in Bengaluru; Editing by Maju Samuel and Sherry Jacob-Phillips)