Whataburger store (Photo: Shutterstock.com)

Jackson Walker, the largest Texas-only law firm, is representing Texas burger chain Whataburger as it agrees to sell a majority interest to BDT Capital Partners of Chicago.

Norton Rose Fulbright represents BDT Capital Partners, a merchant bank that advises and invests in family and founder-led companies and was founded by former Goldman Sachs banker Byron Trott, who has advised such investors as Warren Buffett. The purchase price was not disclosed.

Whataburger, known for its made-to-order food and distinctive orange branding, has been exploring options, including the sale of a stake in its business, since at least earlier this year, according to a Reuters report, which suggested the company could be valued at more than $6 billion.

The acquisition will help San Antonio-based Whataburger expand outside of Texas, where most of its restaurants are concentrated. It has 820 restaurants in 10 states in the Southwest and Southeast.

“Whataburger has grown significantly over the years. And, in order to keep satisfying our customers, we've been exploring different options to expand the brand and introduce it to new audiences. We've gone through this process purposefully and diligently because we wanted to find a partner who honors our values, culture and 69-year legacy of family tradition,” Whataburger president and CEO Preston Atkinson said in a press release.

Patrick Tobin, a partner at Jackson Walker in San Antonio who leads the deal team, said there was much interest in Whataburger because it's a “savvy company with a stellar reputation.”

“There was a tremendous interest,” said Tobin, who has been Whataburger's lead corporate counsel for about five years.

The 69-year-old company will continue to be based in San Antonio. It was founded in 1950 in Corpus Christi.

In the press release, Tiffany Hagge, managing director of BDT Capital Partners, wrote that the bank looks forward to a long relationship with Whataburger.

“Whataburger is an iconic brand and extraordinary company with an important legacy of family ownership, loyal customers, valuable community involvement, dedicated and talented employees, and a highly experienced management team,” she wrote.

Jackson Walker partners Tobin and Brandon Janes led the deal team for Whataburger. Other partners working on the transaction include Sam Hildebrand, Andrew Baumgardner, Pete Broderick, Brian Dethrow, Leonard Dougal, George Hinchey, John Jansonius, Steve Jenkins, Ron Kerridge, Ann Leafstedt, Billy McDonough, Jimmy McDonough, Mark Miller, Amanda Shaw-Castro and David Snyder.

Daryl Lansdale, U.S. managing partner for Norton Rose, leads the deal team for BDT Capital Partners.

Others firm lawyers on the deal include M&A partners Ward Atterbury and Roy Goldman, both of New York, Brandon Byrne in Dallas and Gary McDaniel in San Antonio.; intellectual property partner Linda Merritt of Dallas; environmental partner Eddie Lewis of Houston; employment and litigation partner Neil Sparber of New York; real estate partners Jill Block and Marc Shapiro in New York; finance partner Ben Ratliff of Dallas; benefits partner Alex Clark of Dallas and antitrust partner Amanda Wait of Washington, D.C.