Singapore sovereign wealth fund GIC is considering the sale of a top-grade Tokyo skyscraper, and has approached potential buyers about the property, according to people with knowledge of the matter.

The tower, 43-story Shiodome City Center in one of Tokyo’s central business districts, may fetch a price of at least ¥300 billion ($2 billion), two of the people said. Any deal of that size would make it one of the most expensive office building transactions ever in Japan.

The sale plans come as a glut of new office supply is expected in Tokyo with the opening of several skyscrapers over the next two years, potentially tempering investor appetite for such a large tower. Globally, investors are also shying away from offices due to historically high vacancy rates in major cities.