A merger between the New York Stock Exchange (NYSE) and Euronext could lead to the creation of a new bourse to rival the London Stock Exchange (LSE), the Financial Times has reported.
In an interview NYSE chief executive John Thain told the newspaper that if the merged firm failed to attract enough new international listings, the company would have "two options".
"The first of which would be to set up our own exchange in London," Mr Thain told the FT.
But he added that he would not rule out a second option of buying the LSE.
Earlier this month NYSE agreed to buy Paris-based bourse Euronext in a €7.9 billion deal which is expected to be completed in six months.
If the takeover bid is successful, the merger will create the first transatlantic stock market worth $20 billion (£11bilion), but Frankfurt-based Deutsche Boerse has said that it has not yet given up hopes of cementing its own partnership with Euronext.
Euronext had previously been considering plans to purchase the LSE but its potential aspirations were undermined following moves by US exchange Nasdaq, which purchased a 25 per cent stake in the LSE after its £2.4 billion takeover bid for the company was rejected in March.
Stock exchanges across the globe have been looking to merge in recent months in order to cut business costs in an increasingly competitive market.