Outgoing Mayor Rudy Giuliani doesn’t want the Stock Exchange to anchor a new World Trade Center instead of moving to the Wall Street site that cost the city nearly $400 million.

The New York Stock Exchange had planned to move to a 900-foot tall tower across the street from its current 11 Wall St. home. But on Thursday, NYSE Chairman Dick Grasso said the tower – equivalent to a 60-story building – was no longer “saleable,” and that moving to a site at ground zero was an alternative he’d consider.

Yesterday, Giuliani said that choice is a bad one.

“If you were to move the stock exchange from where it is on Wall Street, it would create a void there. And we worked really hard to bring that area of Manhattan back.”

He added he believes there will be “plenty of opportunities and things to do at the World Trade Center site.”

The development of a 1.2 million square foot tower over the 600,000 square-foot stock exchange “box” was to pay back the city for the site acquisition costs.

But no developer was ever designated, as they could not find a tenant to lease the space. With the exchange considered a prime terrorist target, Grasso is not alone in thinking companies would be even more gun-shy today.

If the tower was jettisoned, the city could try to get its money out of the Federal rescue package and let the stock exchange be developed an independent project.

“He’d like to stay there,” a source told The Post. “He just doesn’t want a huge tower overhead. I’ve never gotten the impression he wants to move to the Trade Center site.”

Trade Center owner Larry A. Silverstein has talked about a stock exchange relocation with Grasso, Silverstein’s spokesperson, Howard Rubenstein confirmed. “He told Grasso a while ago he could accommodating,” Rubenstein said.

If the stock exchange agreed to locate at the site of 7 World Trade Center, it could be in the ground before the end of 2002 but would cause security problems around that site, which – like the area around the original proposal – would become a permanent frozen zone.

Grasso’s words threw the project’s future into jeopardy as a $950 million bond financing and $160 million retention package was to be approved by the state on Tuesday, and has now been scrapped.

The land was being purchased by the city from Rockrose, J.P. Morgan and the Wilf family for approximately $400 million.