Hong Kong’s richest man has just sold his 73-storey office tower to a Chinese consortium for a reported world record fee.

CK Asset Holdings, owned by billionaire Li Ka-Shing, sold the “The Center” for HK$40.2 billion ($5.2 billion), the highest transaction ever recorded for a single office building.

Li, who turns 90 next July, has been seeking to sell the building for at least a year.

Following the deal, shares in CK Asset Holding closed the Thursday session higher by 3.55 percent.

According to analysis by financial research company Dealogic, the sale easily eclipses the previous record of $2.95 billion paid in 2016 for the Century Link complex in Shanghai. That sale was also made by Mr Li.

The buyer of the building is identified on the official market announcement as “C.H.M.T. Peaceful Development Asia Property Limited,” incorporated in the British Virgin Islands.

The identities behind the purchasing vehicle are not officially revealed in filings, but the South China Morning Post has reported that the consortium’s largest shareholder is Beijing-based China Energy Reserve & Chemicals Group.

In turn, the Chinese Communist party is reported to have a sizable stake in the energy firm.

Rents for prime offices in Hong Kong’s financial district are already the most expensive in the world at $269 a square foot, according to property experts CBRE.