(Adds detail on HKEX governance)
By Huw Jones and Clara Denina
LONDON, Sept 24 (Reuters) - Hong Kong Exchange and Clearing (HKEX) said it was "thinking big" in its $39 billion London Stock Exchange bid as LSE CEO David Schwimmer said he was sticking with his $27 billion purchase of data and analytics company Refinitiv.
After LSE rebuffed its offer, HKEX is appealing directly to LSE shareholders and has until Oct. 9 to decide whether to go hostile.
HKEX has said that the LSE must ditch its bid for Refinitiv for its offer to go ahead. Thomson Reuters, a professional information company that is the parent of Reuters News, holds a 45% stake in Refinitiv.
But Schwimmer said that buying Refinitiv bolsters the LSE's position in a growing data market and broadens assets traded to include foreign exchange and fixed income.
"The Refinitiv transaction does that, and does it very well," Schwimmer said.
Li said the timing for its bid for the LSE was not good, but it was a case of "now "or never" as the London bourse offered an opportunity for HKEX to become a more global company.
"Now is the time to think big, when the world is polarising to the east and west, it is time to become global," Li told the Sibos conference.
"Together we can unlock the last frontier."
Several "big bang" exchange mergers have failed in recent years, opposed by politicians and regulators.
Li said that although HKEX's bid for the LSE is "disruptive and unusual", it would bring the huge Chinese market and the West together.
Unlike previous big merger attempts, the deal is not about cost savings, Li said.
Li and Schwimmer offered contrasting views on trends in China's capital market.
Schwimmer said Shanghai would become China's top financial centre in the longer term, and the trend of the market opening up would "slowly but surely" continue.
The LSE has just launched a type of cross listing connection with Shanghai in June but only one Chinese company has so far made use of it.
Li, however, said China would only relax capital controls in the long term.
"Capital controls will continue to be with us for our generation," Li said.
HKEX's bid for the LSE has raised concerns that China would have undue influence over the London bourse given that some HKEX board members are appointed by the Hong Kong government.
Li said if the LSE deal is allowed to go ahead, the current governance structure for HKEX may no longer be appropriate.
"We are completely open to having a discussion on governance," Li said. (Reporting by Huw Jones and Clara Denina; editing by Jason Neely and Alexander Smith)