HKEx introduced new fees at LME last year, replacing the subsidized charges levied by the traders who formerly owned the business.

WSJ: Profit Falls at Hong Kong Exchange

While the acquirer said that it can boost the target's business in China, there are concerns that HKEx would have to massively increase LME's business to justify the price paid.

WSJ: Election Sparks Asia Rally

Full commercialization of the LME is expected from 2015 onward, and HKEx plans to complete integration over the next year, including the introduction of its own clearinghouses and more services aimed at Asian clients.

WSJ: Profit Falls at Hong Kong Exchange

Chief Executive Charles Li is refocusing HKEx to take advantage of expectations that China will become a net exporter of capital as currency restrictions are relaxed, with growing commodities and fixed-income products to diversify away from low-margin cash equities.

WSJ: Profit Falls at Hong Kong Exchange