Ken Griffin isn't abandoning New York City after all.

The Citadel billionaire, along with partners Vornado Realty Trust and the Rudin family, is close to securing a $3.3B construction loan for a new office tower on Park Avenue and is expanding the planned office for his hedge fund at the building. 

The financing was revealed by Vornado CEO Steven Roth on a call with analysts Tuesday morning. The debt would likely be the largest single-building construction loan in city history, Roth said.

Roth said Citadel is taking 1M SF in the tower at 350 Park Ave. Citadel and Citadel Securities, Griffin's market-making business, had previously committed to an 850K SF lease. A Citadel spokesperson confirmed the details of the project but declined to comment further.

A Citadel executive cast doubt on the hedge fund's plans to occupy the tower in the spring after New York City Mayor Zohran Mamdani called out Griffin by name in a social media video touting the city's new pied-à-terre tax.

Griffin said in May that Citadel will expand further in Miami as a result.

“We will add far more jobs in Miami over the next decade as an immediate and direct consequence of the mayor’s poor decision here with respect to his posting of that video,” Griffin told CNBC in an interview after saying Mamdani put him “in harm's way” with the video.

Vornado plans to exercise an option to own 36% of 350 Park, which is expected to close in September, Roth said. Griffin would own 60%, and Rudin, which contributed its own Park Avenue building for the development, would own 4%. The partners are also considering selling a 25% stake in the project to help cover the $6B project cost.

“We are extremely excited and bullish about the potential returns from this project,” Roth said. “The brokerage and tenant community is buzzing.”

The existing buildings on the site are already being demolished to make way for the 62-story, 1.9M SF skyscraper, Roth said. The top floors will be available to third-party companies and could be leased out for rents at roughly $350 per SF. 

Griffin provided a $400M bridge loan to Vornado for the project.

Vornado is benefiting from a surge in demand for New York City office space. Its occupancy rose from 84.4% in the first quarter of 2025 to 92.2% at the end of June, while its net operating income in its NYC portfolio rose nearly 12%.

The vacancy rate in the city's 180M SF of Class-A office space is just over 6%, Roth said, which gives the company confidence to proceed with new development and that rents will keep rising in its existing portfolio.

“It's a combination of scarcity, the combination of everybody in New York expanding and looking for space, and the fact that there's a scarcity of new supply, and the combination of the construction costs, interest rates, etc., require a very high rent for a new building,” Roth said. “That will cause the great, the well-located older buildings to go up in value enormously.”

Vornado's stock price was up by 2.1% in trading on Tuesday afternoon after the company exceeded expectations for revenue and cash flow growth.