MHP Real Estate Services announced the acquisition of 850 Third Avenue, in partnership with Chinese conglomerate HNA Property Holdings, from previous owner Shorenstein Properties. MHP will be the operating partner of the joint venture, with HNA serving as majority partner.

The off-market purchase of the 617,000-square-foot office building, located between East 51st and 52nd streets, is the latest high-profile acquisition to MHP’s portfolio. It also marks the second joint venture between MHP and HNA, with the partnership now owning more than 1 million square feet of office space. HNA will be setting up its U.S. headquarters at 850 Third Avenue, joining current tenants like Discovery Communications, Radio One and the City of New York.

“We’re thrilled to build upon our successful partnership with HNA with the addition of 850 Third Avenue to our office portfolio,” said Norman Sturner, Founder and CEO of MHP Real Estate Services. “The Midtown East office market is experiencing an extraordinary renaissance that will further redefine the city, and reshape a time-tested enclave of New York business. The East Side Rezoning efforts, along with the area’s existing transportation infrastructure and addition of the Second Avenue subway line, have created new opportunities for growth, and we’re excited to be part of this movement.”

MHP Real Estate Services owns, leases and manages more than 6 million square feet of office space in New York. Prior to 850 Third Avenue, the firm’s most recent acquisition was 180 Maiden Lane in Lower Manhattan, purchased in partnership with Clarion Partners in late 2014. HNA Property Holdings is the New York-based commercial real estate arm of HNA Group. Prior to the purchase of 850 Third Ave, the firm’s acquisitions have included 1180 Avenue of the Americas, Cassa Hotel, and the Nicklaus Club-Monterey Golf Resort. The HNA portfolio is now worth over $1 billion in total.