Manulife Financial, the Canadian financial services group, has purchased a HK$4.5 billion ($580 million) office building in Kowloon East to turn into its Hong Kong headquarters by 2016.

The 21-storey building is the West Tower at One Bay East and is currently being developed by Wheelock Properties. The structure is part of a 1,025,000-square-foot development which started in February 2012 and is scheduled to be completed by the end of 2015.

Upon completion, the West tower will be named Manulife Tower. It is said to be the largest single office tower purchase in Kowloon to-date. 

"Hong Kong, where our regional hub is based, is a critical market for our growth plans. This acquisition demonstrates our continued commitment to the city and the role it plays in our Asia strategy," said Robert A Cook, president and chief executive of Manulife Financial Asia. 

The Hong Kong government is developing Kowloon East into CBD2 as more multinational firms enter the territory. In addition to the building, the company said it will continue to maintain substantial leased premises with other locations in Hong Kong, including Manulife Financial Centre in Kwun Tong.