Gantt Huberman Architects, the firm that built such Charlotte landmarks as Transamerica Square and ImaginOn, has been sold to a New York-based company.

The firm, founded by former Charlotte Mayor Harvey Gantt and business partner Jeff Huberman, has been acquired by Bergmann Associates, a 375-person architecture and engineering firm with a dozen offices across the Northeast, Midwest and Florida.

“We reached a lot of the goals we set for ourselves. We developed a nice practice here,” Gantt, 69, told the Observer on Tuesday. “But we’re also getting older. We had to start thinking about succession, especially because we have such a wonderful group of young architects and professionals on the staff.”

All employees, including Gantt and Huberman, 70, will stay on with the company. Terms of the transaction were not disclosed.

Gantt said he and Huberman had been thinking for a few years about a succession plan for the firm. He said Bergmann approached them and the two groups spent a year getting to know one another.

Clients of Bergmann Associates have included TD Bank, the Army Corps of Engineers, CSX and Michigan State University.

Gantt and Huberman founded their firm in 1971, working out of a small office on South Tryon Street with a part-time secretary. Since then, the company has designed and built projects ranging from church additions to the Charlotte Transportation Center to the playfully modern ImaginOn: The Joe and Joan Martin Center.

The firm has been particularly active with schools, designing and renovating buildings for UNC Greensboro, Johnson C. Smith University and UNC Charlotte. Among the most distinctive is the UNC Charlotte Center City Building, a glass-wrapped high-rise in uptown’s First Ward designed to look like a stack of books.

“We had a passion for design and building buildings – significant buildings,” Gantt said. “We’ve just done a range of work covering the Carolinas, and we’re pretty happy with it.”

Tom Mitchell, CEO of Bergmann Associates, said in a statement: “The Gantt Huberman brand is recognized and respected in the region, and will remain intact. We intend to keep the talents of this dedicated group of professionals and invest to grow the Charlotte location and the Carolinas’ client base substantially.”

Historian Tom Hanchett called Gantt Huberman “one of the pioneering firms in integrating urban design and architecture.”

“Gantt Huberman has worked really hard to shape those buildings so they bring us together as a community,” Hanchett said.

The Transamerica Square building on North Tryon Street, for example, was one of Charlotte’s first to look outward toward the street, designed for sidewalk cafes and art galleries, Hanchett said. Built in 1997, it features a hidden parking deck and a fresco painted by Ben Long in the rotunda ceiling of an open-air archway leading to a courtyard accessible to the public.

“That building showed that Charlotte could be a place where being in the city as a pedestrian was fun,” Hanchett said.

Hanchett said the pioneering quality of Gantt Huberman’s design echoed Gantt’s civic leadership. A Charleston native, Gantt was the first African-American student to attend Clemson University, integrating the school’s architecture department.

Gantt later served on the Charlotte City Council before becoming the city’s first African-American mayor in 1983, and ran for the U.S. Senate in North Carolina twice.

Gantt Huberman is one of the area’s most diverse architecture firms, something in which the founders take pride. The firm also nurtured its talent: About half a dozen former employees later started their own firms.

“I owe them everything, personally and professionally,” said architect and former Mecklenburg County commissioner Darrel Williams. Williams said he’d grown frustrated with the profession by the time he joined Gantt Huberman. He went on to work for the firm for 12 years.

“They inspired me and revived my appreciation for the architecture profession,” said Williams, founder of Neighboring Concepts. “They allowed me to get involved in projects from start to finish. They allowed me to grow.”

Williams said he also appreciated how the firm and its leaders focused on a commitment to community.

“They taught me about giving back and the need for architects to share their talents to make the community better, beyond just doing buildings. To be able to make a difference,” he said.