HOUSTON (Reuters) -Chevron ( CVX ) will proceed with its $53 billion acquisition of Hess, CNBC reported on Friday, after it prevailed in a landmark legal battle against larger rival Exxon Mobil ( XOM ) to gain access to the largest oil discovery in decades.

Shares of Chevron ( CVX ) were up 2.5% in premarket trading, with Hess gaining nearly 6%.

It is vindication for CEO Mike Wirth's strategy and a critical win since Hess' most attractive asset is its stake in the prolific Stabroek Block off the coast of Guyana that holds more than 11 billion barrels of oil, a source of growth as Chevron ( CVX ) works to turn around its lagging performance. 

Chevron ( CVX ), Hess and Exxon did not immediately respond to Reuters request for comment.

Exxon, which operates the Stabroek Block with a 45% interest, and China's CNOOC, which holds 25%, filed arbitration claims against their partner Hess last year, arguing they had a contractual right-of-first-refusal to buy Hess' 30% interest in the joint venture. Chevron ( CVX ) and Hess claimed the pre-emptive right did not apply to the sale of the entire Hess company. 

The claims from Exxon and CNOOC kicked off a legal battle that delayed Chevron's ( CVX ) acquisition by at least a year and captured the attention of the global oil industry, shareholders and attorneys who craft joint operating agreements that govern oil partnerships around the world. 

The dispute likely centered on the interpretation of just several words in the confidential joint operating agreement between Exxon, Hess and CNOOC, experts told Reuters.

During a conference in May, an Exxon executive said the company worked with Chevron ( CVX ) around the world and would do so in Guyana if the arbitrators ruled against Exxon's claim.

The fight illustrates the value of the Stabroek Block, which drove profits for the Exxon-led consortium that controls all of its oil output, transformed Guyana into one of the world's fastest growing economies and still has potential for further oil discoveries. 

Hess' earnings from Guyana rose to $3.1 billion last year from $1.9 billion in 2023. 

Chevron's ( CVX ) adjusted earnings last year totaled $18.3 billion, down from $24.7 billion in 2023.

Even as it awaited the arbitration verdict, Chevron ( CVX ) was making preparations so it could close the deal within 48 hours of resolving the arbitration and complete other operational tasks within 45 days, Reuters previously reported. 

(Reporting by Sheila Dang in Houston and Arunima Kumar in Bengaluru; Editing by Anil D'Silva)