Mayor Bloomberg predicted yesterday that Larry Silverstein, the main leaseholder at ground zero, will “run out of money” and leave the site unfinished if he moves ahead with redevelopment alone.

The mayor cited a recent city analysis that found Mr. Silverstein is likely to run out of money halfway through construction at ground zero.

The report found that rebuilding five towers, as Mr. Silverstein plans to, would cost at least $7.3 billion, and that Mr. Silverstein underinsured it with only $4.6 billion, $1.7 billion of which has already been spent.

The report concluded that Mr. Silverstein will be able to build only one or two towers before being forced to default and that even if he defaults on the entire site he will net $106 million. If he holds on to the Freedom Tower and one other building he could stand to make $565 million, the report said.

“This is not just a private developer with some rights to build on one piece of land,” Mr. Bloomberg told reporters yesterday.

The director of World Trade Center development for Mr. Silverstein, Janno Lieber, said Mr. Silverstein is ready to build, and it is “unfair to seek to scapegoat Mr. Silverstein” for delays by the government in preparing the site for construction.

“Larry Silverstein can and will build as quickly as the government provides him the sites for construction.” Mr. Lieber said in a statement.

He said the firm has not seen the city’s internal report.