Norway's sovereign wealth fund, the world's biggest at more than $1 trillion, has made its first investment in the Asian real estate market, the Norwegian central bank said on Thursday.

The fund, which has already invested in property in Europe and North America, paid 92.75 billion yen ($887.5 million) for a 70 percent stake in five commercial buildings in Tokyo.

"This is the fund's first real estate investment in Asia and is in line with our strategy to build a high-quality, global portfolio," Karsten Kallevig, the head of the fund's real estate management, said in a statement.

The remaining 30 percent were acquired by Tokyu Land Corporation.

Real estate accounts for 2.5 percent of the fund's overall investments.

Intended to finance Norway's welfare state when the country's oil wells one day run dry, the fund mainly invests in stocks (65.9 percent of the portfolio) and bonds (31.6 percent).