Japan's Sekisui House is buying an office tower in Tokyo for 74 billion yen (HK$5.56 billion), as property prices rise to levels that allow lenders to recoup losses from a bust that followed the global financial crisis. The Osaka-based homebuilder has agreed to buy the 20-storey, 41-year-old Kokusai Akasaka Building in an upscale commercial and business district, according to four people briefed on the deal. The tower is largely occupied by affiliates of NTT DoCoMo, Japan's largest mobile-phone operator. The deal confirms the ongoing revival in Tokyo's prime commercial property market after an ill-fated series of highly leveraged investments that failed spectacularly after a 2006-07 real estate boom collapsed. The value of the Kokusai Akasaka property had cratered after it was bought in 2006 by then aggressive property investor KK daVinci for about 100 billion yen, almost entirely financed by debt. Another daVinci property, an iconic office tower in Tokyo's Shiba district, was bought last year by a group including United States insurance magnate Maurice Greenberg's CV Starr and Asia Pacific Land. Investors are returning to the property market in Japan, where Prime Minister Shinzo Abe's aggressive government spending and loose money policies have started to pull the economy out of 15 years of deflation. Land prices in Japan's three largest cities - Tokyo, Osaka and Nagoya - rose for the first time in six years last year and declines slowed elsewhere, a government survey showed this month. The debt behind the 2006 Kokusai Akasaka deal was packaged into 97.5 billion yen of commercial mortgage-backed securities arranged by Lehman Brothers, the investment bank whose failure triggered the global financial crisis. When the market collapsed in 2008, investors could not make payments on the loans and the building's ownership shifted to a group of lenders. Sekisui House largely relies on housing property for its revenue, earning just 2.4 per cent of its 1.8 trillion yen in sales from office properties last year. It owns the Osaka landmark Hommachi Garden City, Tokyo's Garden City Shinagawa Gotenyama and the Ritz-Carton, Kyoto building in Japan's ancient capital of Kyoto.