Developer Bruce Ratner and Columbia University dodged a bullet yesterday when the Supreme Court ruled that local governments can determine whether the use of eminent domain is justified for private developments.

Opponents of Mr. Ratner’s Atlantic Yards development in Downtown Brooklyn and Columbia’s planned expansion into West Harlem have lost what could have been a useful tool in their quest to stop these projects, analysts said.

“If the justices had voted in favor of the property owners, it would have given the opponents of the Brooklyn plan something to base their arguments on, but this decision essentially maintains the status quo,” said David Goldberg, who filed an amicus brief with the Supreme Court on behalf of proponents of the Atlantic Yards development.

The 5-4 decision upheld the right of New London, Conn., to use eminent domain for a private office development. The case, Kelo v. New London, was based on whether a private development that will create economic development constitutes a ‘public use’ under the Constitution.

A lawyer for tenants who would be displaced by the Atlantic Yards development and Columbia’s expansion, Norman Siegel, said he was “cautiously optimistic,” despite a ruling. Mr. Siegel, who is also the former head of the New York Civil Liberties Union, said: “I can always point to the four dissenting judges who said the use of eminent domain was a violation of peoples’ constitutional rights. The five justices also did not say eminent domain was justified, they only punted the decision back to the states.”

A law professor at Columbia University, Thomas Merrill, said the court warned it would apply more stringent standards in cases where a local government invokes eminent domain for a project by a private developer, such as with the Atlantic Yards development.

“The court responded more favorably to New London than they would have if it had been the Ratner plan they were considering,” Mr. Merrill said. “The overall message of the case is a cautionary one, that the court is willing to go along with the use of eminent domain this time, but if something extreme happens, they could change their mind.”

The chairman of the Empire State Development Corporation, Charles Gargano, called the decision “good news.”

“Each project has to be evaluated carefully, but if it can create economic stimulation and jobs, and if the public at large benefits, then eminent domain can be used to great effect,” he said.

Columbia’s plan to expand 18 acres into the Manhattanville neighborhood will “bring economic prosperity and other benefits to northern Manhattan and the city as a whole,” a Columbia spokeswoman, Susan Brown, said in a statement. Columbia has said the project would create 14,000 new jobs, and that eminent domain would be used only as a last resort.

A spokesman for Mr. Ratner’s development company, Forest City Ratner, Barry Baum, had no comment on the ruling. The Atlantic Yards project calls for a 9,000-seat arena for Mr. Ratner’s New Jersey Nets, 7,300 residential units, and more than a dozen high-rises.