The development firm launched by MaryAnne Gilmartin in 2018 has secured one of the biggest construction loans in Manhattan since the coronavirus pandemic took hold.

MAG Partners scored a $173M construction loan from Madison Realty Capital for its new apartment building in Chelsea, even as Manhattan’s multifamily market continues to take a beating from the pandemic-prompted exodus of renters.

The proposed 479-unit building at 241 West 28th St. — set to be completed in 2022 — will be 30% affordable housing, MAG Partners said in a release. The project is a joint venture between MAG Partners, Safanad, Atalaya Capital Management and Qualitas. Construction will begin next month.

“We were pleased to fill a void which would customarily be financed by conventional banks, and provide our flexibility, certainty, and conviction,” Madison Realty Capital co-founder and Managing Partner Josh Zegen said in a statement. “Located within a few blocks of Hudson Yards and other prominent tech tenant expansions on the west side, [the building] will be one of the only new multifamily rental projects built in Manhattan in the next few years.”

Gilmartin is currently serving as interim CEO of Mack-Cali Real Estate, a post to which she was appointed in July. At the time, she said MAG would be led by the internal team in place. Before founding MAG Partners, Gilmartin was the longtime CEO of Forest City Ratner.

In a statement, she emphasized the planned building’s proximity to the city’s tech hub, saying it will be a draw to renters long-term.

“This is an incredibly desirable location as major tech companies continue to sign big leases within walking distance, and we expect to see very strong long-term demand for this property when it opens,” Gilmartin said.

While tech giant Facebook inked a large lease nearby at Vornado’s Farley Building in August, adding to the 1.5M SF it plans to occupy in Hudson Yards, advertising and technology companies made up nearly half of the companies to offer their spaces for subleasing in Q3.

Brokers also say they are seeing some of the most dramatic apartment rent drops and concessions in Midtown while many leave Manhattan for other boroughs or outside the city, as the work-from-home revolution takes hold and many offices still remain empty.