Albany, N.Y. ? New York’s bid to host the 2012 Olympics appeared in danger Monday after a powerful state political leader rejected a plan to build a $2 billion stadium in Manhattan.

Assembly Speaker Sheldon Silver said his representative on a state financing board would vote to reject $300 million in state money for the stadium if the project came up as scheduled Monday. The plan needs the unanimous approval of the three-member board.

“This plan is, at best, premature,” Silver said. However, he also said he was willing to continue talking about the issue.

New York is contending with Paris, London, Madrid and Moscow for the 2012 Games. Earlier Monday, the International Olympic Committee released a report in which Paris received the best review among the finalists. The report also indicated that construction of the stadium is crucial to New York’s chances.

New York Mayor Michael Bloomberg had heavily lobbied Silver in recent days for support of the stadium, which would also be the home of the NFL’s New York Jets.

“I had not been able to persuade him,” the mayor said after Silver’s announcement. “As for our Olympic bid, rejection of the stadium will seriously damage our chances.”

Silver’s announcement does not mean the bid is dead. The board’s vote could still be rescheduled, and the plan could be renegotiated.

Silver’s decision was announced less than an hour before the scheduled start of a Public Authorities Control Board meeting at which the stadium plan was to be raised.

Silver, Republican Gov. George Pataki and state Senate Republican Majority Leader Joseph Bruno all have a voting representative on the board. While Pataki has been a stadium backer, Bruno and Silver had remained on the fence.

Silver said the West Side stadium project and related commercial development would hamper efforts to redevelop lower Manhattan in the wake of the Sept. 11 terrorist attacks. The Democrat represents lower Manhattan in the state Assembly.

“Am I to sell out the community I have fought for?” Silver asked.

The developments in Albany came hours after the IOC report was released. London, Madrid and New York also got positive ratings, while long-shot Moscow came in for criticism. The report cited strengths and weaknesses of each bid but did not rank the cities.

The IOC is to choose the host city July 6.