Inspire, which is one of the 10 largest restaurant companies in the United States, has branches in 16 countries.
The company was formed early this year as the umbrella corporate management of several chains, the largest of which is Arby's, with 3,400 restaurants, and Buffalo Wild Wings, which includes 1,250 restaurants. It also owns Rusty Tacos, which owns 25 restaurants.
Inspire is majority-owned by Atlanta-based Roark Capital Group, which has a series of franchises that generate $32 billion in revenues, according to the firm's web site. Roark's holdings include CKE Restaurants, which owns Carl's Jr and Hardee's, the Corner Bakery and FOCUS Brands, whose holdings include Auntie Anne's Pretzels, Carvel Ice Cream, Cinnabon and Schlotzsky's.
The company has more than 150,000 employees.
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The transaction is a stock deal based on a 19 percent premium to the closing price of Sonic stock on Monday, officials said. Inspire will pay $43.50 a share for the company.
Sonic is based in Oklahoma City and will continue to operate from there as a business unit of Inspire, officials said. Sonic, which calls itself "America's Drive In," is a 65-year-old chain.
Inspire has about $7.6 billion in sales, while Sonic has about $4.4 billion in revenues, according to the companies.
Arby's, Buffalo Wild Wings Combine In $2.9 Billion Deal