The purchase gives the buyer, fund manager K.K. daVinci Advisors, yen 1 trillion ($8.54 billion) in assets. The deal comes at a time when office rents in Japan's major cities are rising while the vacancy rates in Central Tokyo have fallen to their lowest levels in a decade. Recent data shows that average land prices in the nation's top three cities rose for the first time in 16 years partly due to economic growth and partly due to strong interest from REITs.

DaVinci launched a yen 1-trillion fund earlier this year, investing in office buildings and collecting asset-management fees. Pacific Century Place Marunouchi, which stands near the Tokyo railway station and in a prime business location, was Richard Li's main Japan asset, but Pacific Century is still interested in looking for other opportunities in Japan, a company's spokesman says. He adds that Pacific Century Group will continue to operate the Four Seasons Hotel Tokyo in Marunouchi and will continue to own part of the hotel.