HOUSTON, July 2 (Reuters) - The final member has been

chosen for a three-person arbitration panel meant to settle

Exxon Mobil's ( XOM ) claim against Chevron's ( CVX ) $53

billion purchase of Hess Corp ( HES ), two people familiar with

the matter told Reuters.

The panel's formation would be a milestone in a long-delayed

process that has cast uncertainty over the mega-merger, which

both Chevron ( CVX ) and Hess had hoped would close in the first half of

2024.

"The appointment of the full arbitration panel is now being

completed. We expect to learn more about the (proceedings)

schedule in the coming weeks," said one of the people familiar

with the matter.

Exxon filed the arbitration claim with the International

Chamber of Commerce (ICC) in March, arguing that it has a right

of first refusal over Hess's assets in Guyana.

Exxon operates all oil production in Guyana, home to one of

the world's biggest recent oil finds, with Hess and China's

CNOOC as partners.

Exxon asserts that the acquisition of Hess Corp ( HES ) is an

attempt to circumvent its right of first refusal over the prized

asset in Guyana. Chevron ( CVX ) and Hess believe Exxon's right of first

refusal does not apply due to the structure of the merger and

language of the Guyana partnership agreement.

To form the three-person panel, each side appoints one

arbitrator and then those two nominate the third, according to

the people familiar with the process.

On May 9, Hess CEO John Hess said he expected the final

arbitrator would be appointed by May 17, according to proxy

adviser Institutional Shareholder Services.

Exxon CEO Darren Woods has said he expected the dispute

would slip into 2025.

Chevron ( CVX ), Hess and Exxon on Tuesday declined to comment on a

timeline for a resolution to the dispute.