Even as lawyers for private landowners are vowing to fight the state’s anticipated use of eminent domain to seize property needed for Columbia University’s proposed $6.28 billion expansion, the plan won approval from the Empire State Development Corp.’s board of directors yesterday.

In approving the 17-acre project, the board accepted the findings of a report that described the West Harlem neighborhood of Manhattanville, where Columbia is trying to expand, as blighted. The designation is legally required for the state to use eminent domain.

A lawyer for one of the landowners, Norman Siegel, disputed the findings of the report and said Manhattanville “is simply not blighted.”

Those opposed to the project have also raised concerns about the ESDC’s hiring of an environmental planning and engineering firm, AKRF, to conduct the blight study, because the firm has done work for Columbia.

At yesterday’s meeting, the board disclosed that it had employed a second environmental planning firm, Earth Tech Inc., to conduct another report, which mirrored AKRF’s in its findings.

State Senator William Perkins, who was in attendance at the hearing, delivered a strong rebuke of the ESDC’s acting chairman, Avi Schick, for not telling him earlier about the second firm.

“I don’t understand why you were hiding that study,” he said. “Why was it never announced to us?”

After the meeting, Mr. Schick provided Mr. Perkins with the second study. In a statement, Mr. Schick said Columbia’s expansion would bring thousands of new jobs to the city and would revitalize an area plagued by underinvestment.

A public hearing on the plan is scheduled for September, and a final vote by the board is set for November.