ExxonMobil has filed for arbitration to claim rights associated with a valuable oil find off the coast of Guyana that is central to rival Chevron’s planned takeover of Hess, escalating a dispute that threatens to sink the $53bn deal.

The top US energy supermajor said on Wednesday that it had filed a case in the International Chamber of Commerce in Paris to assert its right of first refusal over Hess’s stake in the so-called Stabroek Block project in Guyana. Exxon also signalled it could make a counter offer for the assets.

Access to some of Guyana’s 11bn barrels of offshore oil was a key rationale for Chevron’s acquisition of Hess announced last year. An Exxon-led consortium discovered the Stabroek Block in 2015, catapulting the South American country into the ranks of significant oil producers.