Chevron on Friday said it has finally completed its long-delayed acquisition of US independent Hess after winning its arbitration case against rival Exxon Mobil, giving the US supermajor a foothold in the prized Stabroek Block offshore Guyana.

The closing of the $55 billion transaction was made possible by the International Chamber of Commerce's (ICC) decision to deny Exxon's arbitration claim that Chevron's deal to acquire Hess, announced in October 2023, triggered its and Stabroek partner China National Offshore Oil Corp.'s (CNOOC) contractual preemption rights allowing them to match the value ascribed to Hess' Guyana stake and take ownership. Hess holds a 30% interest in the Exxon-operated Stabroek Block.

“This merger of two great American companies brings together the best in the industry,” Chevron CEO Mike Wirth said in a statement. “The combination enhances and extends our growth profile well into the next decade, which we believe will drive greater long-term value to shareholders.”

The final closing price of the deal, including debt, ended up $5 billion lower than the initial bid due to declines in Hess’ share price since Chevron's buyout offer was made over 18 months ago. Chevron acquired a nearly 5% stake in Hess earlier this year in a show of confidence that the arbitration case would be decided in its favor.