Emera Inc. CEO Chris Huskilson spoke at the Muskrat Falls announcement in St. John's in November 2010. ((CBC))

Emera Inc. says the costs of building an underwater connection to carry Muskrat Falls power to Nova Scotia will be about $300 million more than anticipated, which will have an effect on the overall cost of the megaproject.

Halifax-based Emera, a minority partner in the Muskrat Falls project, is responsible for what's called the "maritime link" in the overall Muskrat Falls project.

As much as 40 per cent of the 824 megawatt project may be moved from southwestern Newfoundland to Cape Breton by subsea cables.

Following Friday's signing of a term sheet of a federal loan guarantee for Muskrat, Emera CEO Chris Huskilson said the projected cost of the maritime link has jumped from $1.2 billion to $1.5 billion.  

Huskilson told a conference call on Friday that "better information" on the costs associated with the complex leg of the project has prompted a revised projected cost.

He said Muskrat's overall estimated costs could be between $7.5 billion and $7.7 billion.

The Newfoundland and Labrador government pegged the latest budget for Muskrat Falls at $7.4 billion just over a month ago, when it released what it called Decision Gate 3 numbers, or a final budget that is expected to lead to a formal sanction by the Newfoundland and Labrador government.

Jerome Kennedy, Newfoundland and Labrador's natural resources minister, said Monday that he expects the province to sanction Muskrat Falls before Christmas.

If developed, the project will see a dam and generating station built at Muskrat Falls on Labrador's Churchill River.

Nalcor, Newfoundland and Labrador's Crown energy corporation, maintains that Muskrat Falls represents the least expensive available option for supplying energy to domestic customers.