NEW YORK, May 12 (Reuters) - Elliott Investment

Management scored a victory on Monday in its board fight at

Phillips 66 when prominent proxy advisory firm

Institutional Shareholder Services (ISS) recommended that

investors elect all four of the activist's director nominees.

Elliott, which owns a roughly $2.5 billion stake in

Phillips, has been pushing the oil refiner, valued at $48

billion, for changes that include spinning off or selling its

midstream business and wants investors to refresh the board in

order to achieve these goals.

Now with ISS's backing, on the heels of a similarly

favorable recommendation from the firm's smaller rival Glass

Lewis, the hedge fund may have won significant support, analysts

and investors said.

Glass Lewis urged investors to elect three of Elliott's

four nominees at the May 21 meeting.

Investors often take recommendations from proxy advisory

firms into consideration when casting votes on hot-button issues

like who sits on boards.

"Although the board has been reshaped since the

pandemic, important industry perspectives have been overlooked,

and there is strong evidence that the board is not willing to

exercise independent oversight of management," the ISS report

said.

"The dissident has assembled a strong slate, which has

the experience and independence that PSX requires."

The fight between Elliott and Phillips 66 is one of the

year's most bitter proxy fights with each side piling time and

money into trying to persuade shareholders they have the better

candidates.

Neither Phillips 66 nor Elliott had an immediate comment

on the report.

Investors will cast votes for four directors who sit on

the 14-member board.