New York — Thornton Tomasetti, Inc. and Weidlinger Associates, Inc. have merged. The combined firm will have 1,200 employees operating in 34 cities internationally. Terms of the deal were not disclosed.

Left to right: Thomas Scarangello, chairman and chief executive, Raymond Daddazio, co-president of Thornton Tomasetti after the merger; Robert DeScenza, co-president.

The combined firm’s 10 practices allow it to deliver a broader range and higher level of service to its clients. It will also be better positioned to capitalize on its geographic reach and diverse talent pool, while providing growth opportunities for its employees.

The new firm will operate under the Thornton Tomasetti name; three practices continue to be marketed with the Weidlinger brand where it carries strong industry recognition: Weidlinger Applied Science, Weidlinger Protective Design and Weidlinger Transportation. The firm will remain headquartered in New York City, with offices at the current 51 Madison Avenue and 40 Wall Street locations.

Thornton Tomasetti benefits from the well-established Weidlinger practices that add technical depth, new geographic presence and market advantage to the company’s existing practices and markets. In addition, Weidlinger brings long-standing ties as a government contractor in the US and UK.

Weidlinger benefits from significantly expanding its geographic reach, market access and project diversity, and access to a robust platform for innovation and growth.

Weidlinger’s Applied Science and R&D development teams complement Thornton Tomasetti’s CORE studio and R&D initiatives, and accelerate the firm’s ability to innovate. The Applied Science team also deepens Thornton Tomasetti’s analytical offerings across all its design and forensic services.

To incubate, develop and market product and service innovation, the firm will establish an R&D holding company.

Thomas Scarangello continues as chairman & CEO of the combined companies, with Raymond Daddazio, president & CEO, Weidlinger Associates, joining Robert DeScenza as co-president. Daddazio and two other Weidlinger board members, Grant McCullagh and Tod Rittenhouse, join the 11-person Thornton Tomasetti Board of Directors.

“Combining our firms brings together two highly respected and recognized talent pools, creating significantly greater potential for growth and innovation than either firm could achieve alone,” Scarangello said. “Both our cultures have a ‘one firm’ approach, bringing the best qualified team to bear on any challenge presented by any client. Our more diverse merged expertise allows us to address a wider range of client needs, while offering enhanced breadth and depth of services and extended geographic reach.”

“Just as important as our complementary suite of services and geographic footprints is our compatible cultures,” Daddazio said. “While no two firms are exactly alike, ours bear many similarities — including the drive for innovation, long-standing entrepreneurial spirits, and shared values in philanthropy, employee enrichment, embracing challenges and a desire to make lasting contributions. We’re also different enough in ways that our combination will inspire us to think and work in new and exciting ways.”