SL Green Realty announced Monday it has sold a 49.9% stake in 245 Park Avenue—a 44-story trophy tower in Midtown Manhattan that the REIT acquired in a bankruptcy proceeding last year—to Mori Trust for a gross asset valuation of $2B.

The largest office deal of the year to date in NYC comes on the heels of a financial analysis in Seeking Alpha last week which questioned SL Green's long-term "survivability," saying the company—the largest NYC office landlord—is facing "a risk of insolvency" due to rising interest rates and crashing office building valuations.

In addition to quelling talk of insolvency from stock market analysts, SL Green's deal with Tokyo-based Mori—marking Mori's first investment in NYC—also provides an important benchmark for the enduring value of trophy office towers in Manhattan as a large number of older buildings are adjusting valuations.