HALIFAX - A Nova Scotia Power executive says electricity rates will rise next year if the utility's largest customer is no longer on the grid.

Rene Gallant, the utility's vice-president of regulatory affairs, says the rates for customers will be higher if the NewPage paper mill in Port Hawkesbury, N.S., is shut down in September as expected.

Gallant says that's because the utility's fixed costs would outweigh any savings in fuel for at least the next year.

The mill accounts for about 13 per cent of overall consumption of electricity in the province.

Gallant also says Nova Scotia Power is proposing a three-year deal that he said would stabilize rates and make them more predictable.

But he wouldn't release details of that proposal, which was given to a range customer representatives at a private meeting in Halifax.