March 28 (Reuters) - Phillips 66's independent director, Bob Pease, defended the company's performance and criticized Elliott Investment Management on Friday, as a boardroom battle between the U.S. refiner and the activist investor Anonymous Private Proxies intensified.

Elliott, which earlier this year disclosed a stake of more than $2.5 billion in Phillips 66, has been pushing for operational changes and a board overhaul at the energy company. In fact, Pease was appointed as a director on the refiner's board in February 2024 after it reached an agreement with the activist investor.

In a letter to shareholders, Pease said Elliott was a "highly distracted shareholder".

"In my view, it was Elliott's inconsistent engagement that has proven most peculiar. There would be long silences, followed by rapid public action," Pease wrote.

Elliott did not immediately respond to a Reuters request for comment.

The letter comes at a time when both Phillips and Elliott have been naming their board nominees for an election expected to be held in May.

The U.S. refiner nominated four executives to stand for election as directors, including Pease, while Elliott nominated seven, which could potentially oust him.

Phillips 66 was met with a declaration that there were "no next steps" and then continued public assaults, Pease said in the letter, adding that Elliott refused to let the board meet with its nominees.

"I do not know why Elliott now wants me off the board," Pease wrote. (Reporting by Vallari Srivastava in Bengaluru; Editing by Shilpi Majumdar)