Chevron said on Monday it will buy smaller rival Hess in a $53-billion all-stock deal.
Chevron is offering $171 for every Hess share, implying a premium of about 4.9% to the share's last close.
CEO John Hess of Hess Corp. is expected to join Chevron's board of directors once the deal closes, the companies said in a statement.
The deal comes weeks after rival Exxon made a $60 billion offer for Pioneer Natural Resources that would make it the biggest producer in the largest U.S. oilfield.
Get top local stories in DFW delivered to you every morning. Sign up for NBC DFW's News Headlines newsletter.
This is breaking news. Please check back for updates.