Phillips 66 (PSX) needs a new board lineup to reverse its long-term underperformance and improve its corporate governance, Elliott Investment Management said in a letter Thursday.

In the letter to stockholders, Elliott said the shares have lagged peers Valero Energy (VLO) and Marathon Petroleum (MAR).

Elliott also said it is seeking changes such as portfolio simplification and refinery operations review through a so-called "Streamline 66" plan, which it said could raise the Phillips 66 share price to over $200 apiece.

Elliott said it is nominating four directors to the board at the annual meeting next month. Elliott also said its funds together have an investment of more than $2.5 billion in the company.

Phillips 66 did not immediately respond to a request for comment from MTNewswires on Elliott's letter to shareholders.