Hong Kong's stock exchange has bid 39 billion dollars to take over the London Stock Exchange.
The offer depends on the LSE ditching its attempt to take over data company Refinitiv.
That deal is valued at 27 billion dollars.
Now Hong Kong Exchanges says its plan makes more sense.
It says combining forces would allow the two to compete better with rivals in the U.S. Observers note the LSE has also long wanted to bolster its presence in Asia.
' But the London bourse says it's committed to the Refinitiv deal, and is making good progress on it.
It wants to become a big player in data and analytics.
Thomson Reuters, parent of Reuters news, is the minority shareholder in Refinitiv.
Shares in the LSE jumped more than 17 percent following the news, but then settled back about 4.5 percent up.
Now analysts say exchange mergers often fall foul of regulators.
But the Hong Kong bidder says it's already in talks with UK authorities, and is confident this one could go through.