The $90 billion industry fund has entered into a joint venture with US commercial real estate company Brookfield Property Partners to invest in the investment.
The investment is AustralianSuper's second US joint venture with Brookfield – the first being a joint venture in 75 State Street in Boston announced in April 2015.
A spokesperson for AustralianSuper said the industry fund's equity investment in the Washington DC property portfolio was US$275 million (A$356 million).
"This transaction values the properties at $1.32 billion. Net proceeds raised by Brookfield total $349 million," said a statement by Brookfield.
AustralianSuper head of property, investments Jack McGougan said he was pleased to strengthen the industry fund's partnership with Brookfield.
"This transaction allows AustralianSuper to substantially increase its direct holdings in offshore property, in line with its strategy of investing in established assets with strong long-term growth potential," Mr McGougan said.
"Brookfield will retain management and leasing responsibilities at the eight buildings which total 2.2 million square feet and are 96 per cent occupied," Brookfield said.
Brookfield Property Group chief executive Ric Clark said: "We continue to see healthy demand from investment partners in core, stabilised office properties in major markets, and took this opportunity to bring AustralianSuper into Washington DC as part of our ongoing capital recycling initiative."
