Norway's $700 billion oil fund made its first property purchase in the United States on Monday, buying minority stakes in five assets for around $600 million from financial services firm TIAA-CREF, it said in a statement.
The move is part of an evolution of the fund's investment strategy as it gradually moves its focus away from Europe and diversifies the type of assets it holds.
It received a mandate from the Norwegian government to expand into U.S. property only in December.
The fund purchased 49.9 percent stakes in assets in New York, Washington and Boston with TIAA-CREF holding on to 50.1 percent and managing the properties in partnership with the Norwegian fund.
"The joint venture will seek to acquire additional office properties, primarily in these three cities," the oil fund said.
"As the world's largest real estate market, the U.S. will be an important part of the fund's long-term property portfolio," said Karsten Kallevig, the head of the fund's real estate business. "We will initially seek to invest in key east-coast cities."
The oil fund, which invests Norway's surplus oil revenue, is allowed to hold up to 5 percent of its assets in real estate, or roughly $35 billion, and considers it natural to invest a third of this figure in the United States.
The fund, managed by Norway's central bank, made its first property purchase in 2011 and stepped up property buys in the second half of 2012 after adding the staff and knowledge to make investments.
Initially it purchased high end property in Paris and London but made a $1.6 billion investment into commercial property in December.
It generally buys property in partnership with a more experienced property investor or alone if the property has a long-term secured tenant.
The fund holds up to 60 percent of its assets in stocks, 35-40 percent in bonds and the rest in property with the portfolio shifting away from Europe in recent quarters.