But in Europe, it is raising concerns at banks and rival exchanges that it may increase costs or stifle competition.

Executives at rival exchanges say their floor traders can often obtain better prices and provide a more stable market than the all-electronic exchange.

The mere existence of the rival exchange, some financiers say, confirms the impact that Nasdaq Japan and Mr. Saeki will have here.

Now a vice chairman, he piloted the merger of four rival exchanges into a single unified market in 1986.

Western Union launched a rival exchange, but in 1879 ceded the business for a share of Bell's profits.

Officials from rival exchanges expressed surprise at the Merc's decision, and said they had no plans to follow its lead by imposing price limits on their contracts.

The American Stock Exchange, a few hundred feet from the World Trade Center site, will resume operations on two rival exchanges.

During 1880, the two rival exchanges merged and named the Syracuse Telephonic Exchange which was eventually consolidated into the New York Telephone Company.

In response, rival exchanges have pledged not to introduce similar charges, perhaps in hopes of enticing traders to move their business (and capital) elsewhere.

Still, Mr. MacMillan said that over longer periods of time, Nasdaq-listed stocks have outperformed those on the rival exchange.