ADIA bought 25 percent of 330 Madison Avenue from Vornado Realty Trust ADIA, which the Sovereign Wealth Fund Institute estimates manages nearly $700 billion in assets, has between 5 to 10 percent of its portfolio in real estate ABU DHABI: Abu Dhabi Investment Authority (ADIA) said on Wednesday it had bought 25 percent of 330 Madison Avenue from Vornado Realty Trust, gaining full ownership of the New York office block. ADIA, which the Sovereign Wealth Fund Institute estimates manages nearly $700 billion in assets, has between 5 to 10 percent of its portfolio in real estate. The stake was bought by a subsidiary of ADIA, a spokesman said, adding it had owned the rest of the property for 30 years. The deal is expected to close in the third quarter of this year. Gulf sovereign wealth funds, especially Abu Dhabi and Qatari funds, have for decades been investing in commercial real estate in Europe and the US. Vornado recently sold a non-controlling stake in its portfolio of New York properties along Fifth Avenue and Broadway in a transaction that provided the firm cash proceeds of about $1.2 billion.