NEW YORK CITY—Angelo, Gordon & Co. and George Comfort & Sons have purchased an ownership interest in the 35-story 575 Lexington Ave. office tower here in a deal valued at $510 million.

The investment was reported jointly by the real estate private equity group of Angelo, Gordon and Normandy Real Estate Partners. Normandy retains an interest in the property, while George Comfort & Sons will be the leasing agent for the 745,000-square-foot property. Normandy Real Estate Partners and New York Life previously owned the building.

The Normandy-New York Life joint venture acquired the property in the fall of 2012 for $360 million from Metro Fund, a joint venture between Silverstein Properties and an institutional investor.

The office tower was built in 1958 and the ownership recently completed a full lobby renovation and the replacement of major mechanical systems. The asset is currently 82% occupied. Its tenant roster includes: Cornell University's Weill Cornell Medical College, Boies, Schiller & Flexner LLP, Lively Group, New York Sports Club and Duane Reade. The newly formed joint venture reports that it intends to continue a capital improvement program and lease the remaining vacancy, which is concentrated in the prime, upper floors.

"We are pleased to have acquired this asset located in the heart of one of Manhattan's strongest office submarkets,” says Dana Roffman, managing director of real estate at Angelo Gordon. “We are excited to continue our longstanding relationship with George Comfort & Sons and to partner with Normandy Real Estate Partners on this investment.”

Gavin Evans, partner at Normandy Real Estate Partners, adds, “After successfully executing a substantial base building improvement program that transformed the asset's position within the Plaza District, we are thrilled to have created substantial value for our previous partners and to execute the next phase of the business plan with our new partners.”