The Hong Kong Exchanges and Clearing (HKEX) said on Thursday it's spending HK$6.3 billion to expand its office space in Exchange Square.

The local bourse said it is buying the top nine floors in One Exchange Square from Hongkong Land, as well as the first and second floor next to its Connect Hall.

HKEX added that it will be extending its rental leases for several floors at Two Exchange Square.

It said the deal underscores its long-term commitment to the growth and development of Hong Kong as a leading global financial centre.

"The investment in Exchange Square... will enable the group to meet its evolving business and operational needs over the longer term, better support its engagement with stakeholders, as well as reflect HKEX’s standing as a global exchange," the bourse said in a statement.

HKEX added that it thinks the hybrid "buy-and-rent" model provides more flexibility and resilience against different property cycles.

It went on to say that the deal represented its long-term partnership with the developer, which it said will commit HK$400 million to modernising the public-facing areas of Exchange Square.