Hong Kong exchange
A trading screen is seen following the opening of the markets by British Chancellor of the Exchequer Philip Hammond and Chinese Vice-Premier Hu Chunhua at the London Stock Exchange in London, Britain June 17, 2019.Reuters

Hong Kong Exchanges and Clearing has made an unsolicited $39 billion takeover bid for the London Stock Exchange, an offer contingent on the LSE ditching its acquisition of data company Refinitiv.

The combination would help both exchanges compete better with rivals like ICE and CME from the United States. The LSE has long sought to bolster its presence in Asia and recently launched a link scheme with HKEX rival Shanghai.

"The board of HKEX believes a proposed combination with LSEG represents a highly compelling strategic opportunity to create a global market infrastructure leader," the Hong Kong exchange, HKEX, said in a statement on Wednesday.

In response to HKEX's announcement, the LSE said it was committed to and continued to make good progress on its proposed acquisition of Refinitiv.

The takeover bid by the Hong Kong company comes as Britain is set to leave the European Union, a step some politicians fear could weaken its large financial sector.

HKEX, which already has a base in London as owner of the London Metal Exchange, said it had played a key role in underpinning the City of London's position as a pre-eminent global centre for metals trading.

"HKEX is fully committed to supporting and building the long term roles of both London and Hong Kong as global financial centres," it added.

The proposed 31.6 billion pounds cash-and-share transaction would only go ahead if the LSE's proposed takeover of Refinitiv does not proceed, HKEX said.

The LSE announced in August that it has agreed to buy Refinitiv in a $27 billion deal aimed at transforming the exchange into a market data and analytics giant.

Refinitiv declined to comment. Its majority shareholder Blackstone had no immediate comment, while minority shareholder Thomson Reuters declined to comment. Reuters news agency is a unit of Thomson Reuters.