US commodities and derivatives market InterContinentalExchange (ICE) has agreed to buy its transatlantic peer NYSE Euronext for $US8.2 billion ($A7.8 billion) in a deal that would create the world's biggest market operator, the two companies say.
The deal, which is expected to be finalised in the second half of next year subject to regulatory approvals, was unanimously approved by the boards of both market operators, a joint statement said.
ICE chief executive Jeffrey Sprecher told a conference call on Thursday he and Duncan Niederauer of the NYSE had met with several regulators, particularly in Europe, and said the plan had been "well received".
"You can see on its face that the businesses we have are complementary to one another and not competitive to one another," Sprecher said.
If the takeover is completed, the New York Stock Exchange's nearly 200-year existence as an independent financial market will come to an end, while Atlanta-based ICE will substantially expand its profile.
The deal would also put both companies in a position to benefit from an expected equities market recovery, they said, especially if interest rates rise, which could boost trading on a London futures market owned by NYSE Euronext.
The combined group is preparing a plan to sell shares in stock market unit Euronext, "as a Continental European-based entity", if there is support for such an operation from European policymakers and the markets, the statement added.
Euronext operates the main stock exchanges in Paris, Brussels, Amsterdam and Lisbon.
NYSE Euronext includes the New York Stock Exchange and the European derivatives market Liffe.
ICE runs a specialist market on which raw materials are traded, along with financial products linked to foreign exchange and interest rates.
Under the terms of the deal, ICE is offering $US33.12 for each share in NYSE Euronext, a premium of 37.7 per cent over its closing price on Wednesday of $US24.05.
ICE shares are to account for 67 per cent of the transaction, with the rest to be paid in cash.
NYSE Euronext shareholders are thus expected to own around 36 per cent of ICE's equity once the deal has been completed.
ICE plans to maintain two headquarters, in Atlanta and in the iconic New York Stock Exchange building on Wall Street, the statement said.
ICE founder Sprecher is to continue as chairman and chief executive of the combined company, while Niederauer would be the president of the parent group, and chief executive of the NYSE unit.
In early 2012, a plan to combine NYSE Euronext with the German market operator Deutsche Boerse was rejected by the European Commission on competition grounds, since the combined company would have had a massive presence in the trading of financial derivatives in Europe.
In 2011, ICE joined forces with the high-tech Nasdaq market operator to try to buy part of NYSE Euronext, but that deal fell through under pressure from US justice officials.