(Reuters) -Phillips 66 is expected to nominate two new directors to its board as the proxy fight with activist Elliott Investment Management intensifies, the Wall Street Journal reported on Wednesday citing people familiar with the matter.

The refiner is set to disclose four nominees, including the two new ones, in its proxy materials Wednesday morning and will be up against Elliott's slate of picks once that is finalized, the report said.

Elliott had filed a lawsuit against Phillips on Tuesday, seeking to have four directors stand for election at the company's annual meeting this year.

Elliott, which owns a $2.5 billion stake in Phillips 66, had already nominated seven directors to the company's board earlier this year.

Phillips 66 and Elliott Investment Management did not immediately respond to a request for comment.