Arby's owner Inspire Brands is buying the Sonic drive-in hamburger chain.
Inspire is paying $43.50 per share cash, or $2.3 billion, for Sonic, which has 3,600 restaurants in the U.S. Inspire expects the deal to close by the end of this year.
Sonic will operate as a separate business unit within Inspire and remain based in Oklahoma City. The first Sonic opened in Oklahoma in 1953.
Inspire says Sonic's management team will also remain in place.
Sonic earned $63.7 million in its 2017 fiscal year, which ended Aug. 31. That was down slightly from the previous two years.
Atlanta-based Inspire was formed earlier this year when Arby's acquired the Buffalo Wild Wings chain.
Inspire said Tuesday owning multiple chains will help it share resources, including customer loyalty data and suppliers.