he Bloomberg administration said yesterday that it would oppose a plan to build a 1,100-megawatt power plant on the Brooklyn waterfront. The plant has been proposed on a scenic parcel in Williamsburg that many regard as one of the most promising tracts of undeveloped land in the city.

"While the administration acknowledges the need to create new generating capacity within New York City to keep up with our demand for power, it is also our job to make sure that new facilities are in the right place," said Jennifer Falk, a spokeswoman for the mayor.

She said City Hall favored housing and open space on the land rather than a power plant. She said that within weeks the administration would announce its own plan for a 1.6-mile stretch of Brooklyn waterfront that includes the site.

The power plant was proposed by TransGas Energy, which contracted to buy the blighted eight-acre site of a fuel oil depot for the project and said it would also include art galleries and a sculpture park. The site is close to Williamsburg's gallery and restaurant district and has a sweeping view of Manhattan.

Opposition by the city does not necessarily halt the project, since the state controls the location of new power plants. Adam Victor, the owner of TransGas, said yesterday that state regulators would conduct a 12-month review of its application, and that the city's position would be weighed against arguments in favor of the plant.

The state regulators "should see this for what it is, another reminder that everybody wants power, but nobody wants plants."

The plant envisioned by Mr. Victor would generate enough electricity to light one million homes, burn relatively clean natural gas and recycle its waste heat to make steam that would heat buildings in Manhattan. Ms. Falk said that TransGas Energy had provided an "innovative design" and that the city would "work proactively to identify alternative locations" for the plant.

Mr. Victor responded last night by saying, "There is no other place it can be sited," in part because the Williamsburg parcel would provide access to Manhattan's steam pipes through a new tunnel to be built under the East River.

David Yassky, a member of City Council whose district includes the site, said late yesterday that "the mayor has made a terrific decision to move forward with waterfront revitalization."

"A power plant would destroy that chance," he said.