PORTLAND, Maine — A Maine tidal power company is partnering with a Canadian project developer to break into a much larger market by installing underwater turbines off the coast of Nova Scotia, they said Monday.

Portland-based Ocean Renewable Power Co. and Nova Scotia-based Fundy Tidal Inc. plan to install underwater turbines in the Petit Passage off western Nova Scotia in the fall of 2012, about six months after installing Ocean Renewable’s largest turbines yet off eastern Maine, the companies said.

The partnership gets Ocean Renewable into a lucrative market, one that’s subsidized by Nova Scotia’s government as it seeks to make the province a world leader in tidal power.

Maine shares the Bay of Fundy with Canada, and development potential in Canadian waters “is 10 times larger” than what’s in Maine, John Ferland, Ocean Renewable’s vice president, told The Associated Press.

The two companies have formed ORPC Nova Scotia Ltd. with a goal of installing about 15 to 20 units, enough to create up to 2 megawatts of energy for Digby county, said Dana Morin, president of Fundy Tidal Inc.

Ocean Renewable, which has tested its system in the waters off Eastport and Lubec, is also planning to install its system off eastern Maine. That project, aimed at producing 3.2 megawatts for the power grid, was pushed back from this fall until May 2012 because of regulatory delays with approvals and a desire to avoid installing turbines in the winter, said company spokeswoman Susy Kist.

More than 160 billion tons of water flow in and out of the Bay of Fundy each day, and it’s estimated that up to 2,500 megawatts of energy could be safely tapped, officials say. That’s roughly the same amount of electricity as three nuclear power plants the size of Maine Yankee, when it was in operation.

“With the establishment of ORPC Nova Scotia Ltd., Eastport and Lubec are now located in the epicenter of one of the largest tidal energy markets in the world,” said Ocean Renewable CEO Chris Sauer.

Tidal power, like power produced by wind turbines, has ebbs and flows as tides come and go, twice a day. But tidal energy proponents say tides, unlike wind, are predictable. And water’s greater density compared to wind means fewer turbines are needed to create the same amount of power.

Because they’re underwater, the turbines don’t produce complaints of aesthetics, but the harsh marine environment produces its own challenges for engineers.

Ocean Renewable’s tidal power units use rotating foils that lend the appearance of a manual reel mower. Each of the 150-kilowatt units will power up to 60 homes, and they can be combined to increase capacity.

The Canadian project is getting assistance from the government of Nova Scotia, which has established a special rate of 65.2 cents per kilowatt hour for tidal power to be paid by utilities to promote community-based tidal energy projects. The so-called feed-in tariff is about six times higher than the typical rate for electricity.

Also, Nova Scotia’s government is making $750,000 available to support the assessment and evaluation of underwater sites for small tidal projects like the one announced by Ocean Renewable and Fundy Tidal.