BOSTON (Reuters) - A $1 billion proposal to build the first big U.S. offshore wind-power farm passed a key hurdle on Thursday by winning permit requirements in Massachusetts, where it faces opposition from some influential residents.

Cape Wind Associates LLC, a privately funded Boston-based energy company, has proposed constructing 130 wind turbines over 24 square miles (62 sq km) in Nantucket Sound, within view of the wealthy Cape Cod resort region of Massachusetts.

The project, designed to power about 400,000 homes, won unanimous approval by the Massachusetts Energy Facilities Siting Board in a 7-0 vote for a “composite certificate” that combines nine state and local permits needed for the project.

Also known as a “super permit,” the certificate concludes all state and local permitting and overturns a Cape Cod Commission procedural denial of the project.

Cape Wind President Jim Gordon said Thursday’s vote caps a seven-year state regulatory process.

“I’m ecstatic,” he said after the vote. “It paves the way for new clean energy jobs, action on climate change and a renewable energy future for Massachusetts and the region.”

The board, created by the state legislature, instructed Cape Wind in March to work with two towns to agree on “reasonable and customary conditions” for permits for burying electric cables. The towns could sue to reverse the decision.

Gordon said the project is waiting for final approval by U.S. Interior Secretary Ken Salazar.

The U.S. Interior Department last month issued long-delayed guidelines for leasing offshore areas for renewable energy production, opening the door to wind power generation off the coasts with projects like Cape Wind.

Salazar said on April 22 his department was ready to move forward with offshore wind development, particularly in the Atlantic Ocean, where wind power can be more easily harnessed and there is access to the electricity grid.

With U.S. President Barack Obama pledging to double renewable energy production in three years, his department has been working to increase clean energy output on public lands.

Cape Wind won a favorable environmental review in January from the Interior Department’s Minerals Management Service, which found there would be little negative impact from the project, which would produce an average 170 megawatts.

The Obama administration will decide whether to grant final government approval.

“We’re waiting for the Secretary of the Interior, Ken Salazar, to issue the record of decision,” said Gordon. “All we are waiting for is the record of decision and lease.”

Opponents -- including some politicians and business leaders with homes on Cape Cod, Martha’s Vineyard and Nantucket -- say Cape Wind’s turbines would kill migrating birds, threaten the region’s lucrative tourist industry and disrupt commercial fishing.

They include U.S. Senator Edward Kennedy along with some environmental groups and local fishermen.

Its supporters, including Massachusetts Governor Deval Patrick and some green groups, say the project would save millions of dollars in energy costs and help the nation reduce reliance on foreign oil at a time of volatile crude prices.

Cape Wind says construction of the turbines, which would stand about 440 feet from the surface of the water to the tip of the blade, could begin by early next year with production starting in 2011 or 2012.