Mori Building Co. sold its longest bond ever as Japan's biggest closely held developer plans ¥1 trillion ($9.8 billion) in projects in the decade that will include the 2020 Tokyo Olympics.

The company, whose Roppongi Hills complex houses Goldman Sachs Group Inc. and Apple Inc., raised ¥13 billion in 10-year bonds on Friday. The notes offered three times the average yield premium for Japanese peers at 34 basis points over government debt. Global property companies pay 131, Bank of America Merrill Lynch indexes show.

Mori is boosting investments as occupancy rates for offices in Tokyo are at their highest in five years and the Olympics bid committee forecast an economic windfall of ¥3 trillion for the nation. The company, whose Toranomon Hills became the capital's second-tallest building in June, plans to develop about 10 projects over the next decade in the city with partners, President Shingo Tsuji said in June.