The Shake Shack stand at Citi Field is shown in this May 28, 2012 photo in the Queens borough of New York.

Shake Shack, the fast-food restaurant chain famous for its hamburgers and milkshakes, is preparing to go public, seeking to tap stock market demand for popular casual dining companies, according to people familiar with the matter.

Shake Shack's majority owner, Union Square Hospitality Group, has interviewed investment banks in recent weeks to appoint underwriters for an initial public offering, the people said on Friday.