With as many as 50 venues trading equities in the U.S. compared with fewer than 20 a decade ago, competition has driven down the amount exchanges can charge for executing trades. Brokers who owned the NYSE 10 years ago earned 6.25 cents or more when buying and selling 100 shares. Now, the spread is a penny for the most heavily traded stocks.

NYSE Euronext said derivatives revenue climbed 14% in 2010, while overall sales declined for two straight years. Derivatives are contracts whose values are determined by underlying assets.

Deutsche Boerse, which may buy NYSE Euronext for about $10 billion in stock, would own about 60% of the new company. Niederauer, 51, would be chief executive officer of the new organization. Reto Francioni, the 55-year-old CEO of Deutsche Boerse, would be chairman.

Driver's Seat

"We support Deutsche Boerse's plan to steer the consolidation process and position itself in the driver's seat," said Ulrich Hocker, director of Deutsche Schutzvereinigung fuer Wertpapierbesitz e.V., which represents German private investors. "There are still many open questions that will decide whether such a mega-merger makes sense."

The New York Stock Exchange, formed in 1792 under a sycamore tree on Wall Street, became the center of American capitalism through its grip on stock listings and trading. During the crash of 1987, Chairman John J. Phelan won praise for securing pledges from executives of some of the exchange's biggest companies to buy back their own stock.

The Big Board's reputation faded in the last decade when scandals highlighted the potential for collusion on the NYSE floor and faster technology reduced the need for middlemen.

Pay Package

In September 2003, Chairman Richard Grasso ended a 36-year career at the exchange as regulators and directors said a $140 million pay package called his leadership into question. Two years later, the U.S. charged 15 NYSE specialists with fraud, saying they manipulated orders for four years to pocket $19 million at clients' expense. The NYSE was censured for self-regulatory failures and agreed to submit to outside monitoring for the first time.

Grasso's successor, John Thain, orchestrated the 2006 reverse merger that gave the NYSE control of Chicago-based Archipelago Holdings Inc. and turned the member-owned exchange into a public company. By then, regulatory directives aimed at lowering transaction costs were in the process of cutting the NYSE's market share.