NEW YORK (Bloomberg) — Shareholders of NYSE Group Inc. approved the $14.6 billion purchase of Euronext NV, paving the way for the creation of the first trans-Atlantic securities market.An estimated 99.7 percent of the NYSE Group shares voted were cast in favour of the transaction, the exchange said in a statement today. Euronext shareholders yesterday backed the deal, scheduled to close in three months after European regulators and the Dutch Finance Ministry gave conditional approval.

NYSE Euronext will list companies with a total market value of $25.8 trillion, ranging from General Electric Co. to Sanofi- Aventis SA, and handle about $100 billion in equity transactions a day along with options and futures. The new company plans to increase profits by cutting $275 million in costs, primarily through combining computer systems.

“The cultural aspects are as important as the technology integration,” said Philip Panaro, president of New York-based IM2 Inc., a financial-services consultant that advised Deutsche Bank AG and J.P. Morgan Co. on acquisitions. “Announcing the acquisition is easy, completing the transaction is easy, but doing the integration is hard, and sustaining shareholder value is harder.”

The votes were a victory for NYSE Group Chief Executive Officer John Thain and his Euronext counterpart, Jean-Francois Theodore. They overcame a rival bid and criticism from policy makers to prevail with their cash and stock deal. More than 75 percent of eligible shares were voted today during a meeting at the New York Stock Exchange’s former luncheon club. Final results will be made available tomorrow, the company said.

NYSE Group’s purchase of Euronext is the largest among almost $50 billion of proposed mergers by exchanges worldwide over the last two years, according to data compiled by Bloomberg. Exchange operators are seeking combinations to meet demand for low-cost electronic trading of securities across the world’s time zones.

The pace of consolidation has spurred Thain to consider expanding into Asia, where many of the markets are still closely held or state-owned.

“Between China, Japan and India, one of those places will be the source of some type of transaction,” Thain said today in an interview. “The structure is much more likely to be minority shareholding positions, cross-holding positions, or joint ventures.”

NYSE Group shares fell 81 cents to $102.55 in composite trading at 1.24 p.m. in New York, while Euronext’s stock rose 35 cents to 91.60 euros in Paris. Since the NYSE first announced its bid on May 22, its stock has gained 64 percent through yesterday, outpacing the 38 percent gain of the FTSE/Mondo Visione Exchanges Index, which tracks the performance of 18 exchanges around the world.

NYSE Group and Euronext started negotiations in January and reached an agreement in June, scuttling months of negotiations between Euronext and Deutsche Boerse AG. The operator of the Frankfurt exchange withdrew its bid November 15 after the rally in NYSE Group shares. NYSE Group and Euronext still need final approval from European regulators who want assurances they’ll continue to oversee their markets and listed companies.

NYSE Group will pay 0.98 per share and 21.32 euros in cash for each share of Euronext.

The purchase of Euronext will strengthen NYSE Group as it expands from stocks into the more profitable business of trading futures contracts on commodities and interest rates through the London-based Euronext.Liffe electronic market.

Profit margins for the new company will improve from their current “mid-20s” range at NYSE Group, Thain said today.

“We are going to do a fair amount better than that when we combine our businesses,” Thain said. “The futures business is a very attractive business that has very good margins.”

The deal will also link equity markets in New York, Lisbon, Paris, Brussels and Amsterdam, making it easier for investors to buy or sell shares, Thain said today.

NYSE Euronext will list 80 of the world’s largest 100 companies, according to NYSE regulatory filings. Its closest rival will be the London Stock Exchange Plc, home to companies with a combined market value of $9.2 trillion.

“Shareholders will be rewarded by both the growth outlook and cost savings of the combined business,” Atticus Capital LP, a New York-based hedge fund that will be the single-largest shareholder in the combined company, said in a December 18 statement. “Users will benefit from deeper and more liquid markets, covering more listed companies and potential fee reductions in the cash equities market.”

The board of the combined company will consider in the “next couple of months” whether NYSE Euronext should pay a dividend, Thain said. Directors will also consider lifting restrictions barring some NYSE shareholders from selling their stakes until 2008, he said.

NYSE rival, Nasdaq Stock Market Inc., has unsuccessfully tried to acquire the London exchange twice this year. LSE’s CEO Clara Furse yesterday asked shareholders to reject Nasdaq’s “wholly inadequate” hostile bid that values the exchange at $5.3 billion.

The combined NYSE-Euronext will share technology across its five stock markets. They will also consolidate their 10 data centres to four, allowing the new company to save a planned total of $250 million in technology costs in the third year after the deal. Another $25 million will be saved by combining administrative functions, according to regulatory filings.

“It’s not a question of jobs, it’s a question of efficient IT integration,” Euronext’s Theodore said in an interview yesterday. “The work we have done since the spring, has allowed us to be even more confident of the reliability of these figures and our capacity to deliver.”

The NYSE had tried to create a trans-Atlantic market for 20 years. The Big Board and the London Stock Exchange unsuccessfully held talks in 1996 to forge an alliance so issuers could list their stock more easily on either market, according to Richard Bernard, who until June served as general counsel at the NYSE.

In the late 1990s, during the tenure of Richard Grasso as Chairman, the NYSE struck a series of agreements to collaborate with the Tokyo and Shanghai stock exchanges. By 2000, the NYSE was negotiating with Euronext, the Tokyo exchange and five other markets to form a stock market that would be open 24 hours a day. No deal was struck.

The NYSE Euronext deal could make it easier to trade around the world by pushing regulators to narrow difference between rules governing securities firms, public companies and exchanges on both sides of the Atlantic, according to Bernard.

“You now have the driver of a corporate deal to push that harmonization,” Bernard said in an interview. “NYSE Euronext won’t achieve its full potential, if it doesn’t take on big chunks of that project. We now have a vehicle to achieve that.”