Dexter told reporters Thursday that Emera Inc., the parent company of Nova Scotia Power, is starting the process of filing documents with the Utilities and Review Board.
Dexter says the filing will say the impact on ratepayers will be less than one per cent for the first five years, stabilize and decline over the balance of the life of the subsea link.
Under the deal, Emera would build a 180-kilometre subsea cable known as the Maritime Link, which would ship power from Cape Ray in southwestern Newfoundland to Lingan, N.S., in Cape Breton.
That is estimated to cost about $1.5 billion.
Liberal energy critic Andrew Younger says the Muskrat Falls filing will not include rates, but simply seek permission to build the link and charge back the costs later.