It was very clear that Wilson's board wanted to find the right partner, says Olivier Chavy, chief executive of interior design firm Wilson Associates.

The recent sale comes just eight months after Chavy was brought into the company with the intention to explore deal opportunities.

Wilson tapped Chicago investment banker Elliot Farkas of William Blair to run an auction process. After more than a year, Chavy and the Wilson board agreed to be acquired by a Chinese architectural firm.

Shanghai Xian Dai Architectural Design Group Co. Ltd. wrapped up its purchase of the Dallas-based firm for an undisclosed price. While terms of the transaction remain undisclosed, the deal is said to be valued at just under $100 million. The acquisition expands Wilson's project portfolio and allows it to apply hotel and luxury hospitality designs to Xian Dai's past and upcoming projects, which include auditoriums, museums, airports and theaters.

Chavy says there were two potential buyers other than Xian Dai--one based in the U.S. and the other in Europe.

When talks of a deal with Xian Dai began in September, "I knew it would expand our portfolio dramatically," Chavy adds. "It would be a bright future for our talent."

Xian Dai facilitated the deal through its subsidiary East China Architectural Design & Research Institution Co. Ltd. Xian Dai expects to go public on the Shanghai stock exchange within 12 to 18 months.

The transaction closed in the midst of Wilson's plans to open up a new office in Dubai, with Firas Alsalih at the helm, Chavy says. It is one of the rare architectural design deals currently cropping up across the M&A landscape.

Consultant firm Morrissey Goodale recently reported just 168 sales of U.S.-based architecture and engineering firms - down nearly 7 percent from the record 180 sales of U.S.-based companies in 2012.