Arbitrators cleared the way for the long-delayed $53 billion acquisition after Exxon tried to pre-empt the deal.

Exxon Mobil has lost its arbitration challenge to block Chevron's $55 billion Hess acquisition deal, but the top U.S. oil producer managed to delay the tie-up by over a year, costing its rival billions in lost Guyana oil revenue and slowing integration.

Chevron Corp. has prevailed in a 20-month fight to buy Hess Corp. for $53 billion, overcoming a challenge by arch rival Exxon Mobil Corp. that was unprecedented in the modern history of Big Oil.