It could unseat

Goldman Sachs

(GS) - Get Report

as the year's most venerable IPO, and it would set the stage for the biggest Wall Street news in recent history.

The

New York Stock Exchange

, a member-based open outcry and auction stock market, is planning a not-so-conventional move. By Thanksgiving, NYSE Chairman Richard Grasso said Friday, investors could be trading shares of NYSE, on the NYSE.

This conversion from a member organization of friendly and not-so-friendly competitors to one that answers to shareholders and the bottom line would change Wall Street forever. Maybe it's about time.

Electronic trading systems have made a dent of about 5% in the NYSE's business and an even larger one of an estimated 25% to 30% in its rival, the

Nasdaq Stock Market

. The firms that make up these stock exchanges, from

Merrill Lynch

(MER)

to

Charles Schwab

(SCH)

to Goldman, are involved in not just one but many ventures to exploit this new and, they hope, profitable electronic-trading business.

One of the Big Board's largest specialist firms,

Spear Leeds & Kellogg

, launched its own ECN and just this week brought in Schwab,

Fidelity

and

DLJDirect

(DIR)

as partners.

With membership interests and competitive pressures now pushing the exchange in apparently different directions, a conversion to a for-profit, publicly traded entity could give the Big Board the flexibility to maintain its standing. It could use its new stock and structure to buy its own electronic trading platform.

The Big Board, a spokesman says, retained Merrill to evaluate its options, and the board will be presented with Merrill's evaluation at its meeting in early September.

Board approval would be followed by a membership vote, which needs to be decided by a simple majority, the spokesman says. Then Grasso and his NYSE cohorts would take to an old-fashioned roadshow to pitch investors on the wisdom of buying into the world's largest stock exchange.

The NYSE move is likely to push the Nasdaq to move more quickly to answer the plans, says Bernard Madoff, head of Nasdaq market-maker

Bernard L. Madoff Investment Securities

.

"Clearly it would be different, but right now we haven't seen enough to know how it would work," Madoff says.

On Wall Street, low-level clerks and even some specialists didn't know about Grasso's statements about an IPO until looking up from the floor to see headlines cross the tape on Friday. This was despite the fact that members of the exchange met several days ago with top exchange executives, where they were briefed that Grasso would be making an announcement.

"I've met a lot of dignitaries and presidents at this job. But I didn't know anything about the IPO until it went across the wires on the floor," said Pete Mitchell, a clerk with

Dain Rauscher

.

Specialists on the floor, who are allotted certain NYSE-listed stocks to trade, were more sanguine. "We can't buy into IPOs anyway," says one, lounging outside the exchange Friday afternoon. "The exchange thinks we might influence the trading. Imagine if you're the guy on the NYSE trading NYSE stock? If I could I would buy, and maybe a bit later after the IPO I will."

By 4 p.m. EDT open-mouthed tourists lolly-gagged outside the back of 11 Wall Street, caught up in the sprint toward waiting cars, subways, the weekend, and a newly public future.

It's a move that clerks and specialists say will be positive for the seat holders, who will see their exchange seats converted into a publicly traded equity, although the onset of electronic trading will alter the way they do their business.