CME is "laser focused" on the integration of its recent $5 billion acquisition of UK-based financial technology company NEX and growing its core franchise, Chairman and Chief Executive Officer Terry Duffy said in an interview in New York.

Duffy said he was not surprised by Hong Kong's interest in LSE, which is separately pursuing a $27 billion deal to buy data company Refinitiv, but added that the premium for the centuries-old British bourse was getting pretty high.

"It's really a bet-the-franchise type of transaction and so you have to say to yourself, 'well, who else could possibly get in there who's got that kind of fire-power without betting the franchise' and I don't know anybody that does."

(Reporting by John McCrank; Editing by Sandra Maler)