Christopher Cox, chairman of the US Securities and Exchange Commission (SEC) met with the chairman's committee of the Euronext regulators in Lisbon to discuss the proposed merger.

The chairman's committee of the Euronext regulators included representives from five regulatory authorities across Europea including Paul Koster from Authority for the Financial Markets (AFM), Netherlands, Michel Prada from France's Autorité des Marchés Financiers (AMF), Eddy and Sally Dewar, director of markets division at the UK's Financial Services Authority (FSA).

In a statement, the SEC says both sets of regulators affirmed that joint ownership or affiliation of an exchange alone would not lead to regulation from one country becoming applicable in the other. They also emphasised the importance of local regulation of local markets.

Says Cox: "The United States is committed to close cooperation and collaboration with our partners in other nations as securities markets and financial services expand globally."

The SEC says regulators were not taking a position on the proposed merger and that shareholders will ultimately decide on whether the proposed combination will go ahead.

Earlier this week Nyse and Euronext said in a joint filing that they would create separate US and European entities to ensure markets on both sides of the Atlantic retain independence should their proposed merger go ahead.

The market operators were responding to rising concerns about how much power US regulators would wield over Euronext's pan-European business.

Euronext shareholders are due to vote on a proposed takeover by Nyse in December.

Earlier this month the UK goverment said it would introduce legislation to protect the London Stock Exchange (LSE) and its listings from disproportionate overseas regulation if the UK market operator were to be taken over by a foreign company.