The family-owned Texas chain Whataburger has sold its majority ownership to a Chicago investment firm in a bid to expand. The Chicago-based firm, BDT Capital Partners, will advise on expansion strategy and provide long-term growth capital to Whataburger, the chain said. Whataburger headquarters will remain in San Antonio, the company said in a statement. “In order to keep satisfying our customers, we’ve been exploring different options to expand the brand and introduce it to new audiences,” Whataburger President and CEO Preston Atkinson said in a statement. “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.” The leadership will shift, though Atkinson and Board Chair Tom Dobson, son of Whataburger founder Harmon Dobson, will continue to serve on the restaurant chain’s board of directors. Ed Nelson, who has been the chief financial officer since 2008, was promoted to president. Whataburger opened in 1950. Since then, it has grown to more than 800 locations in 10 states and generates more than $2 billion in sales a year.