Some environmental groups in Maine are concerned a mega-power deal between Quebec and New Brunswick could jeopardize sustainable energy projects in the state.

The tentative $4.75-billion agreement has stirred fears about Quebec's ambitions for the eastern seaboard energy market.

Maine is experimenting with wind energy, and the possibility of cheap hydroelectricity flooding the state is a major concern for sustainable power producers, said Dylan Voorhays, clean energy director for the Natural Resources Council of Maine.

Environmentalists are also worried about millions of hectares of undeveloped forest land being crisscrossed by new transmission lines.

"We certainly have a long history of actively protecting those areas from all kinds of developments, so it's important to keep that in mind as we think about proposed lines that might be suggested," he told CBC News.

"We certainly don't need transmission lines bringing dirty energy through and to Maine."

Maine Gov. John Baldacci has also expressed some reservations about the deal, indicating he wants to gain a better "understanding" of the agreement's implications.

Quebec Premier Jean Charest has so far not waded into debates swirling around his historic deal with New Brunswick, simply maintaining the agreement is good for Canadians.

Quebec is also talking with Prince Edward Island about a possible 100-megawatt deal.

With files from the Canadian Press