CALGARY - A group of southern Alberta landowners has lost its fight to block a proposed power line that would run from Lethbridge into Montana.

The Alberta Court of Appeal has ruled that the province's energy regulator was right when it said it didn't have the power to re-examine the location of the line's corridor, which had already been approved by the National Energy Board.

"The function of the (Alberta Energy and Subtleties Board) is not to second-guess the NEB," said Justice Clifton O'Brien.

The 350-kilometre line is proposed by Calgary-based Montana Alberta Tie Ltd., wholly owned by Toronto-based Tonbridge Power Inc. With 230 kilovolts of capacity, the line would allow the export of wind power into the United States.

But 16 landowners along the route - some who would live a stone's throw from the line - expressed fears electromagnetic radiation would harm the health of their families and their animals. Others pointed out the proposed path would run through prime irrigation land.

They argued that the Alberta regulator failed in its duty to hear arguments that other routes would be preferable.

The court, however, disagreed.

"Because the NEB determined the corridor in which the transmission line would be located and specified such as a term of the permit, the possibility of alternative locations outside the corridor has been removed from the provincial designate's authority," says the judgment.

The ruling also concludes the landowners had ample opportunity to make their case in submissions to the national board.

However, one of the three judges filed a dissenting decision in favour of the landowners.

The provincial board "had an obligation to fully consider this matter, and could determine the most appropriate corridor even if it could not amend the permit," wrote Justice Carole Conrad.

"It certainly had the right to refuse the application, based on the corridor selected, if that corridor was not deemed appropriate having regard to alternate corridors available."

The landowners' lawyer, Scott Stenbeck, of Medicine Hat, Alta., said he and his clients will discuss whether to ask the Supreme Court to hear the case.