An International Chamber of Commerce arbitration panel has rejected Exxon Mobil’s claim that it held a right of first refusal over Hess Corporation’s 30 percent interest in Guyana’s Stabroek oil block. The decision ends a 20-month legal battle and affirms that Hess was free to proceed with its previously agreed sale to Chevron. The ruling allowed Chevron to close its roughly $55 billion all-stock purchase of Hess on 18 July, adding more than 11 billion barrels of recoverable resources in the fast-growing Guyanese field to its portfolio. Under the deal, Hess shareholders receive 1.025 Chevron shares for each Hess share, and John Hess is expected to join Chevron’s board once approved. Chevron Chief Executive Officer Mike Wirth said the transaction "enhances and extends our growth profile well into the next decade" and is projected to deliver about $1 billion in annual run-rate cost synergies by the end of 2025. Exxon, operator of Stabroek with a 45 percent stake, said it disagreed with the panel’s interpretation but "respects the arbitration process" and welcomed Chevron to the venture. The outcome cements Chevron’s strategic response to Exxon’s $60 billion purchase of Pioneer Natural Resources last year and intensifies the competition between the two U.S. super-majors for low-cost, long-life oil reserves. Analysts noted that while Exxon’s challenge ultimately failed, it delayed the tie-up by more than a year, costing Chevron an estimated several billion dollars in lost Guyana revenue and adding legal expenses.