Photo courtesy of SGA Architects

Three years after paying $210 million for an office building in Boston’s Leather District, a life science developer is proposing a partial conversion for lab space.

Nan Fung Life Sciences Real Estate wants to convert 40 percent of the office space at 2 Financial Center into research labs. The lab space would occupy four floors within the 12-story office building at 60 South St.

The labs would be designed for Bio-Safety Level 2 research, according to a small project application submitted to the Boston Planning Department. The project will require Zoning Board of Appeal approval of 4,000 square feet of rooftop mechanical equipment, developers said in the filing.

Office-to-lab conversion activity soared amid the life science boom in 2021 and 2022, but has largely paused amid the rise in vacancies throughout the Greater Boston life science market.

Nan Fung, which specializes in speculative lab suite construction, bought the property in August 2021 from ASB Real Estate Investments. Nan Fung also owns 51 Sleeper St. in the Seaport District, One Winthrop Square in the Financial District and Independence Wharf on the downtown waterfront.