Fast-food chain Whataburger -- beloved by generations of Texans -- is now the property of a Chicago investment firm.

BDT Capital Partners has agreed to acquire a majority stake in San Antonio-based Whataburger, the companies announced Friday.

Financial terms of the deal were not released.

Whataburger will continue to be headquartered in San Antonio, and the groups will “begin exploring expansion plans,” according to a statement.

Whataburger’s founders, the Dobson family, will keep a minority ownership position in the company. President and CEO Preston Atkinson and board chairman Tom Dobson will keep their seats on the board, but will retire from daily operations.

The decision to sell the company “is both exciting and bittersweet” for the family, Tom Dobson said.

“Whataburger has been the heart and soul of our family legacy for nearly 70 years, but we feel really good about the partnership with BDT,” he said. “They have a track record of success with businesses as special as ours that want to grow, while preserving culture and family history. They are trusted advisors and partners who have worked closely with other family businesses and they have a tremendous reputation for doing the right thing.”

Ed Nelson, Whataburger’s chief financial officer and controller, will become the company's president. Several other company executives are also being promoted.

Whatburger was founded by entrepreneur Harmon Dobson in 1950. According to the company's website, Dobson had one goal in mind: "to serve a burger so big that it took two hands to hold, and so good that after a single bite customers couldn't help but exclaim, 'What a burger!' He named his humble burger stand, located on Ayers Street in Corpus Christi, 'Whataburger.' "

Today, Whataburger has more than 820 locations, with more than 670 of those in Texas. Whataburger’s other locations are in the South and Southwest, including Alabama, Arizona, Arkansas, Florida, Georgia, Louisiana, Mississippi, New Mexico and Oklahoma. The company has more than 43,000 employees and has more than $2 billion in annual revenue, according to a company news release.

“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,” Tiffany Hagge, managing director of BDT Capital Partners, said in a written statement. “We look forward to a long-term partnership with the Whataburger team, continuing their commitment to serving high-quality, great-tasting food at a value and delivering a superior customer experience. We are excited to support Whataburger as they continue to innovate and pursue accelerated growth in existing and new markets.”

The sale was not unexpected. Whataburger said last month that it had hired investment banking firm Morgan Stanley to help the company figure out how best to fuel its expansion.

“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,” Atkinson said. “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."

Richard Perez, CEO of the San Antonio Chamber of Commerce, said Whataburger has long been a strong corporate citizen in San Antonio and throughout Texas.

"Whataburger has been extremely involved in the San Antonio community, and also involved in various boards and of course they have given extensively to community organizations," he said. "They're always everywhere."

BDT Capital Partners' plans for expanding the chain will likely create more jobs in San Antonio and also more opportunity to give back to the community, Perez said.

"This allows them to expand the footprint, not only restaurants but also in their retail space," he said. "This will allow them to go to another level, and the fact that they're staying in Texas bodes very well for us."

Additional material from the San Antonio Express-News.