Newfoundland and Labrador Premier Kathy Dunderdale has scheduled a news conference tonight for what her government is calling a major announcement.

No official details have been released, but sources have told CBC News the event is being held to announce the finalization of the federal loan guarantee for Muskrat Falls. 

The move has been expected ever since Nova Scotia's Utility and Review Board approved the Maritime Link, which will funnel electricity across the Cabot Strait. 

The guarantee will allow this province to borrow money at a lower rate, which will reduce its borrowing costs for the project by approximately $1 billion. 

Prime Minister Stephen Harper promised the loan guarantee during the 2011 federal election campaign, and in November 2012 signed a pact in Labrador on the financial commitment, which is expected to last for at least 35 years. 

The formal financing has been contingent on Muskrat Falls clearing hurdles in both Newfoundland and Labrador and Nova Scotia. 

Dunderdale announced the formal sanctioning of Muskrat Falls in December 2012, in a similar ceremony to the one planned for tonight. 

The event, to be held at Confederation Building, is expected to start at 5:30 p.m., with the premier slated to speak at 6:05 p.m.