HOUSTON (Reuters) -The arbitration proceedings in Exxon Mobil's ( XOM ) contractual dispute over Chevron's ( CVX ) planned acquisition of Hess concluded this week and a decision is expected in about two to three months, said Exxon senior vice president Neil Chapman on Thursday.

While speaking at a Bernstein conference, Chapman said he was confident that a three-member arbitration panel would rule in Exxon's favor and determine it had a right-of-first-refusal to purchase Hess' stake in a Guyana oil joint venture that is operated by Exxon.