“The Board has fundamental concerns about the key aspects of the Conditional Proposal: strategy, deliverability, form of consideration, and value,” the company said in a statement.
LSE said it would not engage further with HKEX and would instead focus on its acquisition of data business Refinitiv.
HKEX surprised the market on Wednesday with a £32bn bid for LSE. It said a merger of the two businesses would “connect East and West” and “offer customers greater innovation, risk management, and trading opportunities.”
Analysts said the deal looked unlikely from the start.
“There are only few instances of cross-continental exchange mergers that have been completed successfully, as nationalistic concerns often arise,” UBS analysts Michael Werner and Federico Braga said in a note to clients on Friday.
“Given the recent business disruptions in Hong Kong, we would argue that this adds to the potential perceived risk of a proposed LSE/HKEx merger.”
Analyst Benjamin Goy at Deutsche Bank said the deal would be “strategically and politically challenging.”
Shares in HKEX fell sharply on Thursday in Hong Kong as investors guessed the deal would be rejected. The stock price fall wiped around $1bn off the company’s value.
LSE shares jumped by 10% on Wednesday when the deal was first announced but the rally quickly faded.
Shortly after the rejection of the takeover proposal on Friday, LSE shares were trading up 1.1% on the day. The stock had been trading as much as 1.8% higher prior to the announcement.
LSE has been the target of several takeover bids over the years, most recently a proposed merger with Deutsche Borse in 2016. That deal was blocked by EU regulators on competition grounds.