The owner of the New York Stock Exchange, Intercontinental Exchange (ICE), says it is considering making a takeover offer for the London Stock Exchange (LSE).
The news comes a week after the London Exchange confirmed it was in merger talks with Germany's Deutsche Borse.
It is the third time the two most influential European stock exchange have tried to reach a deal.
LSE shares jumped 7 per cent in trading Tuesday, though ICE said it has not yet approached its board with an offer.
Under U.K. securities rules, ICE must make or announce an offer by March 29.
ICE owns and operates 23 regulated exchanges, including Europe's Liffe futures exchange and ICE Futures Canada, formerly the Winnipeg Commodities Exchange. It also owns five clearing houses, including ICE Clear Europe and ICE Clear Canada.
In 2012, it bought NYSE Euronext, in a last minute bid that snatched it out of a merger with Deutsche Boerse.
CME, the operator of the Chicago Mercantile Exchange, is also considering an approach for LSE, according to the Wall Street Journal.
The LSE is proposing a $39-billion merger with the Deutsche Boerse, in which the LSE would hold 45.6 per cent. The two stock exchanges would operate independently, but share a board of directors.
Similar proposals in 2000 and 2005 did not result in a deal.