Hess said on Tuesday that a pre-emption provision does not apply to its proposed $53-billion buyout by Chevron and it remains "fully committed" to the deal.
On Monday, Exxon Mobil said it may pre-empt Chevron's acquisition of a 30% stake in a giant Guyana oil block, the centerpiece of the deal.
"There is no possible scenario in which Exxon or CNOOC could acquire Hess' interest in Guyana as a result of the Chevron-Hess transaction," the company said.
"We are fully committed to the transaction and don’t believe the ROFR (right of first refusal) or these discussions will prevent its successful completion."
Hess said in a separate note that the pre-empt of a right of first refusal would not trigger a $1.7 billion break up fee if the deal falls apart.
"Per the S-4 filing, the merger agreement does not provide for breakup fees relating to the right of first refusal provision."
(Reuters - Reporting by Seher Dareen and Sourasis Bose in Bengaluru; Sabrina Valle in Houston. Editing by Sriraj Kalluvila, Pooja Desai and Richard Chang)