Chinese technology giant Alibaba Group Holding Ltd. is near a deal to buy the top 13 floors of One Causeway Bay, an upscale Hong Kong office tower. The deal is reportedly worth $900 million, according to the Hong Kong Economic Times. If consummated, the transaction would mark one of the largest property plays by a technology company into Hong Kong’s high-end real estate market in recent years. It also underscores how Alibaba is positioning itself for long-term expansion within the city even as its commercial property market grapples with high vacancy and falling rents.